AGTireTalk The Future of Tire Technology 2019-09-16T11:34:38Z https://agtiretalk.com/feed/atom/ WordPress https://agtiretalk.com/wp-content/uploads/2016/06/cropped-AG-Tire-Talk-Logo-No-Words-1200-Square-32x32.jpg James Tuschner <![CDATA[4WD Tractor TRACTION: Pulling 550 hp Implement]]> https://agtiretalk.com/?p=1507 2019-09-16T11:34:38Z 2019-09-14T03:57:48Z Below is question posed to tire manufacturers from Illinois:

  • In 4WD Tractor application, if implement requires 550 hp and standard duals are not providing adequate traction (can’t go wider with triples), what is your recommendation and how does it compare to tracks on transport & field speed?

Precision Inflation, LLC
Ken Brodbeck: VP of Technology

How to make your 4WD Tread Lightly and Pull Like a Locomotive!

An implement requiring 550 hp is definitely a heavy tillage requirement and demands the tractor be set up specifically for this high draw-bar application.

The tractor must have all three attributes properly set in order to provide comparable draw-bar pull to track machines:

  1. Tires:
    1. Base or standard tires may need to be up-sized to wider and higher load capacity tires
    2. Standard 620 or 710 width tires should be replaced with IF 800/70R38 for the widest and longest footprint possible
  1. Tractor Ballast:
    1. For heavy tillage, 4WD tractors require more ballast
    2. If 4WD wheel slip is over 8 to 10%, more ballast is required
    3. Typically, the rule of thumb is 105 lbs. per engine horsepower
    4. 550 hp x 105 lbs./HP = 57,750 lbs.
    5. Weight split should be 55% front and 45% rear for Ag Applications
    6. Front weight = 31,800 lbs.
    7. Rear weight = 26,000 lbs.
    8. Minimum PSI with IF 800/70R38 tires
      1. Front = 9 psi
      2. Rear = 6 psi
    9. If this is an extreme traction application, most tractors can be ballasted to 60,000 lbs. using the same 55/45 weight split
  1. Tire Pressure:
    1. Quite often the implement or tire dealer will over-inflate the original tires OR use the same smaller tire psi for the larger tires
    2. Over inflation shrinks the footprint and makes the tractor prone to power hop and higher wheel slip
    3. The tractor needs to be weighed on a scale or estimate weight using the tractor manufacturer ballast calculator to determine both front and rear axle loads
    4. Tire pressures then need to be set 1 to 3 psi above the minimum tire pressure unless the machine has a tire inflation system that allows the tires pressure to be maintained daily
  1. Speed:
    1. It is important to note transport speed differences between tires and rubber tracks with heavy hitch loads
    2. Often, rubber belt tractors have speed limits for weight and distance in transport. Tires do not have these limitations.  See rubber track machine advisory placard below:

Bottom Line:

Once you have completed the above 3 steps, the 4WD tire tractor will walk softly and run right with its rubber belted cousin with no problem- just like in the photo below!

And with a $100,000 lower price tag.

 

Camso
Jeff Staab: Product Line Manager – Track Systems

Farming equipment has become extremely specialized to respond to the numerous application requirements of today’s agricultural industry. For the high horsepower tractor range, original equipment manufacturers offer, direct from the factory, vehicles that are equipped with either tires or tracks. As machines keep getting bigger and faster and they pull larger implements, we’ve seen increased demand for tracks from the market. For end-users, the mobility of tracks in many applications remains a key differentiator.

Why Tracks to Increase Traction?

High horsepower tractors have to pull implements at various soil depths, in addition to completing multiple functions in a single pass in the field. Combine this with the need to complete these tasks at higher speeds and/or in as fewer passes as possible, tracks are helping farmers get the work done efficiently, especially when dealing with soft field conditions. In such conditions, performance is in the 1-5% slip range for tracked tractors due to longer and larger footprint, while duals will run in the 8-12% slip range. Slip reduction helps to maintain higher speeds in the field and to take advantage of the tractor and implements’ high performance.

Farmers appreciate the ride quality in the field with the tractor on tracks: they experience less vertical bouncing and no power hops. While they have to give up some ride comfort when roading, they like the narrower transport width going down the road, only 36 inches of track on each side of the tractor, making it more than four feet narrower than a tractor equipped with duals.

 

Maxam Tire International
Greg W. Gilland:  Business Development & Ag Segment Manager

Each agricultural operation requires equipment designed to maximize the pulling or transmission of a tractor’s horsepower (HP) to pull the desired implement through the field.

4WD tractors using tracks have the advantage of a constant footprint on the soil due to the length of the track and available contact footprint over the soil.

The larger the 4WD tractor (increased horsepower), the larger an implement the 4WD tractor can pull.

The options available for ag tires employed on larger 4WD tractors to transmit the machine horsepower, increase traction and ensure the required flotation (as compared to 4WD tracked tractors) are summarized below:

 

In the case of 4WD tractor applications, the choice of machine brand and horsepower available will dictate the options or size of tires that can be employed to deliver the traction expected to pull large implements.

Agricultural tires are designed based on their size geometry, materials and air chamber to carry a certain amount of weight at a given ground speed and to fit a certain wheel base or equipment.

In 4WD tractors the on-going challenge is to reduce the size or width of the tractor despite the fact, that with larger implements on the design board, more horsepower is being applied to all new 4WD tractors coming to the ag market. The below chart created by New Holland for the T9000 summarizes some of the width challenges and solutions offered by various tire options:

One solution, that has been tested with successful results, is to convert a tractor to a larger diameter VF Tire that simultaneously provides the tractor with reduced width solution, greater traction (tread length) and lower soil compaction (air pressure):

Provided below is a table comparing the above tires in terms of load carrying capacity in equivalent 4WD tractor applications based on tire specifications provided by both the Tire and Rim Association (TRA) and the European Tire and Rim Organization (ETRTO):

In summary, when challenged with a 550 HP tractor that needs greater pulling power at reduced widths (no triples – less than 14 feet) convert your tractor to larger diameter tires that can be used in duals giving you greater traction, footprint and reduced machine width. VF Technology continues to bring new solutions that are re-defining the use of tires to meet the growing challenge of larger, more powerful tractors.

When you compare the advantages of tires to tracks, tires are easier to maintain both in terms of mounting, impact of tracks on overall machine weight, vehicle maintenance and the overall fuel efficiency of the tractor. Machine speed and fuel consumption will be based on the load the machine is pulling either in the field or on the road whether with tracks or on tires.

Maxam Tire is actively working to develop VF Technology ag tires to meet the evolving and increasing weight demand of the next generation of ag equipment, with our first VF tire solution being our Agrixtra N (N for narrow) high clearance sprayer VF 380/90R46, with 4WD tractor VF technology coming to market over the next few years.

 

CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

John Deere 9620R Example

Weight
The first thing to do is determine the actual gross weight per axle. The Base weight of this tractor model is 43,420# and the engine horsepower is rated from 370 to 620 hp. We have to assume we have the 620hp engine.

Ballast
The minimum recommended gross weight should be 62,000# with 60% of the weight on the front axle and 40% on the rear. You need to add a minimum of 18,580# of additional weight via suitcase, axle or wheel weights. If adding weights does not accomplish the gross weights or weight distribution, you can add weight via liquid ballast.

Inflation
Check your inflation pressures on all tires. Normal inflation pressures for this setup would be 10psi in the front and 8psi for the rear tires.  You may be able to lower your inflation pressures but you need to consult the tire manufacturers’ load and inflation tables before you do this. If the gross weight and the distribution is correct and traction is still an issue you should add additional weight approaching a gross weight of 74,400# with the appropriate distribution. This additional weight gets you to 120#\ hp.

We have no information concerning additional weight to the drawbar that would be exerted by our implement so minimal consideration will be calculated into our recommendations.

In Sum
Setting up this tractor with the gross weight at 120#\hp with the correct distribution and correct inflation pressures should provide more than adequate traction.

If that is not the case, another option to consider would be renting or borrowing a smaller implement that has lower power requirements. If this situation is a normal, regular operation you might consider replacing your tires with IF or VF type tires that will provide longer footprints, increased flotation, and increased traction.

 

BKT USA, Inc.
Dave Paulk: Manager Field Technical Services

Managing traction is important to controlling costs and efficiencies on a farm. Too much tire slippage can increase fuel and labor costs. The more lugs that can be put on the ground, the better the traction and performance will be. When high horsepower tractors are used with heavy implements, higher air pressures may be required to support the increased weight. Higher air pressures in standard rated tires can lead to less traction, more tire slippage, and a greater increase in soil compaction. Having the ability to reduce air pressures without damaging the tire will give a larger tire footprint and better traction.

Tires with IF and VF technology may help with traction and lead to less tire slippage and better flotation. IF tires are rated to carry 20% more weight at the same air pressures as a standard tire. VF rated tires are rated to carry 40% more weight at the same air pressures as standard tires. If a tire can carry the same weight at 20% to 40% less air pressure respectively, this allows for a larger (wider) tire foot print with more of the tire and lugs on the ground for traction. This allows less slippage and fuel savings. Tires provide better traction as their inflation pressures are decreased. IF and VF tires enable a tractor to carry more weight on the road without having to widen the tractor with triples. They can be used to minimize soil compaction where important. Looking at these tires to replace standard rated tires would be a first step in solving this problem.

When comparing tires with tracks for traction, there are pros and cons with both. Tracks provide more traction and flotation in wet soil and tracks have a longer foot- print. Tracks generally work with less slippage, about 5% compared to 8-15% for tractors. This should give tracks the advantage of pulling heavy equipment where triples can’t be used. Field speeds with tracks should be equal to, and maybe a little better, for tracks in this proposed application.

Often times, farms are scattered, and tractors must be transported on the highway. Pneumatic tires work better with this application.  Another question is the cost of operating a tractor with tires vs. tracks.  The cost of maintaining the suspension on a tractor with tracks is expensive compared to that of a tractor with tires. On a tractor with tires, you basically only have to worry about tires, wheels, and hubs. Tracks are more expensive than tires and there are many more moving parts on a tractor with tracks.

As a comparison, if tires can be used and give the required traction, they are much less expensive to maintain. They ride and handle better, and generally last longer than tracks in highway use.  While there advantages for tracks, the farmer must decide what is best for his application and what costs he can live with.

 

Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

Every farmer strives for the highest efficiency on power and torque transfer from his tractor to the ground. He seeks the lowest slippage, lowest fuel consumption, lowest compaction, and fastest speed possible. Not all conditions can be achieved, yet many combinations can be applied to meet proper needs. Each element must be approached step-by-step.

Ballast

First, we consider the transfer of power to the ground. It begins with balancing the total tractor weight and its power (as the weight distribution depends on tractor power). There are general rules to follow when determining this balance. Heavy tillage must consider between 100 to 120 pounds per tractor engine horsepower. In this case, a 620 hp tractor would need between 62.000 to 75.000 pounds of total tractor weight. As for weight distribution between front and rear axle, it will depend on how much down force the implement applies to the rear axle. Broadly speaking, a starting point of 55% front-45% rear and up to 60% front-40% rear is the right point.

Inflation Pressure

Secondly, focus on how to transmit power to the ground. A track system does not require any adjustments; but remember that the rubber track must be tensioned well, to avoid slippage on the wheel. Tires, on the other hand, must be adjusted; to monitor inflation pressure (per the tire manufacturer recommendations). Once the correct weight for the tractor has been established, we may define the correct inflation pressure, depending at what speed we intendent to drive the tractor.

Speed

On conventional tires, (not IF or VF technology) the load capacity increases when we reduce the working speed (at same inflation pressure). That being said, it is very important to be aware of the machine’s speed that the tractor-implement will be working. Follow the tire manufacturer recommendations to assure the tire footprint is the largest possible for the load; with more lugs on the ground for traction and larger footprint for lower compaction. One point to consider, while using dual fitment, is that the load capacity is reduced by 12% on each tire –meaning that the load capacity should not be doubled. By adding duals, you gain 1.76 times the single load capacity. The reduction is even higher when using triples. Each tire load capacity is reduced by 20%, conveying a triple set will carry 2.4 time the load of a single tire (not 3 times).

IF /VF Tires

On IF and VF technology tires, there is no gain in load capacity when speed is altered. Once the load has been established, the inflation pressure may be determined. The advantage of IF and VF technology tires is that they can carry more load at the same inflation and inflation pressure can be reduced with the same load. A lower inflation pressure means more lugs on the ground and larger footprint with lower compaction. An important point to mention is: there is an opposite relation between traction and flotation. When flotation is increased (for extreme compaction) the lug pressure is reduced on the ground (less traction), and slippage increases. Each farmer will have to find the right compromise between power transfer efficiency (less slippage) and compaction (flotation).

Solutions

With a better understanding of setting up tires on a tractor, we can now discuss solutions to when the tractor does not perform as expected. If there is excessive slippage, it may be because of the following two main reasons. First—too much pull from the implement (meaning the implement requires more power as the tractor can deliver). Or, the tires are not transmitting the power to the ground.

In the first case, the only option is to reduce the implement power needs (for example: reduce the implement penetration) or reduce the working speed. It is also possible that the soil conditions are not normal-optimal for the operation (such as: too wet). Resulting in more power as in normal conditions. In this case, the farmer would need to schedule the work for a better soil condition if possible.

For the second reason, the farmer would need to check first that the inflation pressure is correct (as per tire manufacturer recommendations) for the tractor weight. If correct, and there is no possibility to add triple tires- additional weight may be added (if not yet at the maximum weight allowed). Or the tires may be changed to provide a larger and wider footprint and ensure they are R-1W tread (20% deeper lug height as R1 tires) or the lug design (45-degree lugs, Progressive Traction technology). Also, it is possible to change to IF or VF technology, allowing the reduction of inflation pressure and increase the footprint (more lugs “biting” the soil). This usually requires a change in rims (VF technology uses wider rims).

In most situations, a correct tractor weight and distribution (actual tractor weight – not the manuals estimated weight), with the correspondent tire inflation pressure is enough for an efficient performance. Remember to always consult your trusted tire dealers or equipment dealer for additional information.

 

Alliance Tire Americas
Nick Phillippi: National Product Manager

With massive loads and high horsepower, today’s top-of-the-line tractors are placing huge demands on tires. There are three levels of commitment an operator can undertake when it comes to maximizing the performance of the tires and the equipment: managing the inflation pressure properly (easiest), switching to low-pressure tires (moderate), and, ideally, using a central tire inflation system to maintain optimum pressure (fully committed).

In tires, it’s all about inflation pressure. With a massive tire like an 800/70R38, the difference between 23 psi (which many farmers will inflate to because it’s easy and going to the max seems like the safe choice) and 12 psi (which is optimum for field work) is night and day. Just dropping to that lower inflation pressure is enough to transform his tractor into something he didn’t even know he had.

And all it takes is an air gauge, a tire inflation chart and a few minutes to really get the most out of that $400,000 he invested in his tractor.

The next step, especially with a huge tractor, is switching to VF tires. It is possible to “over-tire” some tractors, as Dallas Ransom discussed in a recent blog. But with a John Deere 9620 or a Steiger 620, you’re talking about 50,000 pounds of machine. Nobody makes a tire too big for that.

With that kind of load, VF tires will pay off all day long, especially because you can handle the same load as a conventional radial with 40 percent less inflation pressure. That allows you to get down as far as 8 or even 6 psi and really give tracks a run for their money in terms of traction and flotation.

Of course, the best way to get duals to maximize traction is to lower inflation pressure in the field and only raise it on the road. Under those conditions, the tires should perform equivalently to tracks at all times—while being a lot less expensive and much easier to maintain.

As much as we in the tire industry would love to see farmers stop on the edge of the field to adjust their inflation pressure, the most practical way to ensure that the adjustments are made would be to install a central tire inflation system (CTIS) on their tractor, especially if he or she has made the investment in VF tires.

CTIS technology allows the operator to adjust inflation pressure with an onboard compressor at the touch of a button. In just a couple of minutes, a set of tires can be adjusted to optimum inflation pressure for either field or pavement, low speed or high. CTIS can be easily retrofitted onto tractors, and can cost less than a set of tires. Especially if a farmer is investing in IF or VF tires, CTIS is a great complement to that.

With all the advantages of CTIS—including better traction, improved flotation, more effective transmittal of horsepower to the ground, increased fuel economy and longer service life from your top-dollar tires—investing in the technology begins to return immediately and a good system can pay for itself very quickly.

 

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

The key to any high draft load / heavy tillage applications requires three things.

First, the tractor must be ballasted heavy enough to pin the power to the ground.  As discussed in previous articles we recommend 90lbs to 120lbs per horse power as a guideline for total machine weight.  Additional ballast may need to be added to achieve the proper machine weight.

Secondly, along with total weight,  front to rear weight distribution is also critical.  We recommend a 60/40 (front/rear) weight split as a target.

Lastly, once the tractor is ballasted correctly inflation pressure must be set for optimal performance.

Below is an example of loads and inflation which would work on any model tractor:

600+ HP Tractor (Any Brand) Ballast and Inflation Recommendation

Total Machine Weight    62,000 lbs.

Front Axle Weight            37,200 lbs. (9300 lbs./tire)

Rear Axle Weight             24,800 lbs. (6200 lbs./tire)

Recommended Inflation

710 (Duals) Rear Front 800 (Duals) Rear Front 900 (Duals)
710/70R42 9psi 16psi 800/70R38 6psi 13psi LSW900/50R46 6psi 7psi
IF710/70R42 6psi 12psi IF800/70R38 6psi 9psi
VF710/70R42 6psi 9psi VF800/70R38 6psi 7psi
LSW710/60R46 6psi 12psi LSW800/55R46 6psi 9psi
Singles
LSW1100/45R46 12psi* 17psi
LSW1250/35R46 12psi* 17psi
LSW1400/30R46 12psi* 17psi

*VF agricultural tires when used as singles minimum 12psi (TRA standard)

Tracks machines are different in the fact that they typically sit at or close to the appropriate weight without hanging another piece of iron on the machine.  The down side is that the machine cannot be made any lighter when a lighter less compaction type application is being performed such as planting.

Road transport speeds and distance in track machines are typically reduced due to the wear and tear on the tracks themselves.

In the field I would put up any LSW tire on a wheeled machine against any track machine of similar horsepower and run toe to toe with the track machine.  I have seen time and time again conventional tires tend to not perform as well as tracks or LSW tires due to the propensity to power hop in the field causing the tractor to loose tractive efficiency and therefore being less productive across the field.

Road speeds are also typically higher in LSW equipped machines versus track machines or machines equipped with conventional tires due to road loping issues.  Titan/Goodyear offers expertise in the field with our Ag Specialist Team, with the group’s sole purpose to assist end users with application issues- they will come out and scale equipment and make recommendations on ballast and inflation to ensure optimum performance.

 

Continental Agriculture North America
Harm-Hendrik Lange: Agriculture Tires Field Engineer

As a broad portfolio provider, Continental offers both rubber track and tires for a complete agriculture solution. There are certain applications where each excels and is a better overall fit for the needs of the operation. Farmers should consider investment and maintenance costs, road driving capabilities, transportation width, soil compaction, traction and fuel consumption. To help customers make the right equipment choice, Continental has a team of experienced field engineers who visit and consult with customers in the field. Every application is different, and Continental offers products to meet every need.

Both track and tires can provide superior performance, depending upon the application.

The benefits of  TRACK include:

– Narrower transport width for the same load capacity
– More pulling traction in wet conditions
– Less fuel consumption per acre at high loads and high torques
– Less track width, able to handle row applications in wet and muddy conditions with narrow tracks
– Same footprint area on less track width means less soil deformation energy in total
– No time required to adjust tire inflation pressure
– Less slip rates to transfer the pulling force
– Soil protection, if highest loads needs to be carried (where tires need high inflation pressure)

The benefits of TIRES include:

– Lower investment cost
– Lower vehicle weight
– Lower fuel consumption per acre for lower torque applications, as tracks have more moving parts
– Less heat generation at road speeds
– Lower maintenance costs
– Reduced soil disturbance on end row
– Improved steering on steep inclines
– Uniform soil pressure distribution
– Better ride

Continental heavy-duty farm tires are versatile for applications that need performance in the field and on the road. They have low heat buildup while roading and can be driven loaded and unloaded on both roads and fields. Tires offer low investment and maintenance costs, uniformly distribute soil pressure and are efficient for road transportation. To optimize traction, farmers should reduce the tire pressure to the recommendation stated on technical data sheets. Oftentimes, the inflation pressure is too high creating a smaller contact patch of the tire to the ground which lowers traction.

For an application with full power field work where standard duals are not providing adequate traction and the user isn’t able to go wider with triples, track offers an efficient solution. Continental Trackman rubber track, constructed for the most severe and extreme applications, are able to transfer more torque to the ground and gain greater traction, all with high flotation because of their larger foot-print. This foot-print allows the machine/equipment weight to be distributed across a greater area and lowers the ground pressure, without increasing width as triples would require. Reducing ground compaction equals greater crop yields.

In order to get the power to the ground with the highest horsepower equipment in the marketplace, we recommend market leading guide-lug support system called ARMORLUG®, MAXXTUFF™ wire ply construction providing more ends per inch, and now the patented ARMORLUG® ULTRA that provides 25% more torque capability than before.

 

Michelin Ag
David Graden: Operational Market Manager – Agriculture

As a producer, you are inundated with marketing campaigns, ads, salespeople feeding you opinions as fact, etc. The truth is, if you know what you want to achieve and you know what is available, it will lead you to the decision that meets your needs.

At Michelin, we begin with creating tires based upon a farmer’s value and needs. From there, we teach our sales reps to find the facts and match the right tire based upon those facts. Finally, we close the loop by proving lower total cost of ownership and stand behind our decision by working with you year after year.

In the case of a 4WD machine, pulling an implement that requires 550 hp, there are several cost-effective tire options for you that can do the job. First, begin with listing your needs:

  1. Traction
  2. Torque transfer
  3. Limited width (triples too wide)
  4. Are you concerned with fuel economy?
  5. Do you have the need to travel between fields at a descent rate of speed?
  6. Have you considered soil compaction and the proven effects on yield?
  7. Have you looked at the different machines and price gaps between each?

Typical tire sizes found on these machines are the 710/70R42 and the 800/70R38. I would recommend going with the VF (Very High Flexion) tires in these sizes in the new Axiobib 2 or Evobib. Each of these tires has been extensively tested and marked with “Inflation Systems Ready” on the sidewall, meaning they are designed to optimize your tire pressures based upon your needs- with the simple push of a button.

Let’s take a look at the air pressures required to transfer 550 hp. When calculating the optimum tire pressures, we need to first know what the machine weighs and calculate the proper weight distribution required to transfer that torque to the ground.

At 6 mph, these machines will require about 95 lbs. per engine horsepower. That comes to 52,250 lbs. total. Next, you want about 55% of that weight on the front and 45% on the rear axles. This weight distribution will eliminate power hop and road loping.

For each of these tires, the front axle air pressure for field operation is 9 psi and the rear axle air pressure for field operation is 6 psi. With a PTG central tire inflation system, for roading, you can then increase the air pressure to maximum psi on the sidewall for each tire and travel at maximum machine speed!

The main difference between these two tires is the Evobib will have a much larger footprint at 6 and 9 psi than the Axiobib 2. Due to the shoulder design of Evobib, the footprint of this tire will actually increase by over 28 additional pairs of lugs on the ground at field operation pressures!

So, in addition to transferring 550 hp to the ground, you want higher road speeds, less fuel consumption, increased yields, and an overall lower cost of ownership, our recommendation is to pair a premium VF tire with a central tire inflation system.

 

Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

When users complain about traction in the field, the first thing that needs to be done is make sure the tractor is set up correctly. Loss of traction could be due to under- or over-ballasting of the tractor, too high of inflation pressure in the tires, or using liquid ballast in the tires. Before we recommend different tire sizes, tire technologies or mobile solutions, let’s get the tractor set up correctly.

For a 4WD tractor, the target ballast weight is 110 lbs per engine horsepower in heavy drawbar pull.  A 620 hp 4WD tractor should have a base weight of 68,200 lbs.  The weight needs to be distributed so that 51% – 55% is on the front axle, and 45% – 49% is on the rear axle. The front-axle target weight would be between 34,782 lbs and 37,510 lbs, and the rear weight would be between 33,418 lbs and 30,690 lbs. I recommend using steel ballast to obtain the weight on the tractor. Using liquid ballast does not damage the tire, but liquid does not compress. Since liquid does not compress, it will prevent the sidewalls from properly deflecting, and will make the tire stiffer. This extra stiffness causes the tire from developing a full footprint, reducing traction in the field. By using the ballast calculator provided by the tractor manufacturer, the machine can be ballasted with the available steel weight package, which provides a front-axle weight of 35,500 lbs (52%) and a rear axle weight of 32,700 lbs (48%).

With the front- and rear-axle weights set to utilize the engine horsepower, the minimum inflation pressure for the tires can be calculated. Assuming the tractor has dual 710/70R42 tires, the minimum inflation pressure needed to carry 35,500 lbs on the front axle is 20 psi. The minimum inflation pressure needed to carry 32,700 lbs on the rear axle is 17 psi. Setting the pressure to these weights allows the tires to develop the largest footprint possible. The pressure in the tires also determines what the ground contact pressure is. In this setup, the ground contact pressure is approximately 22 psi on the front axle and 17 psi on the rear axle.

If the tractor is set up correctly, and it still does not seem to have the required traction (excess tire slippage on firm soil), then it is time to look at the IF or VF tires. IF and VF tires allow the tires to carry the same axle loads at lower inflation pressures. The lower inflation pressures allow the tire to deflect more, allowing the footprint to increase in length. The longer footprint allows more tread bars to make contact with the soil, increasing traction. For a 620 hp tractor, Table 1 shows what inflation pressures are needed to carry the axle load:

Table 1: Minimum Inflation Pressure

The benefit of the IF and VF tires to the user is that the standard radial tires can be replaced with the IF or VF tires, with only an investment in the tires. The Firestone IF and VF tires are approved to go on the same rims as the standard radials, making extra spending on wheels or different mounting hardware unnecessary. The lower inflation pressure increases the footprint area, and provides an improvement in traction and a reduction in fuel usage. The lower inflation pressure also reduces soil contact pressure, helping to limit soil compaction.

When comparing four-track systems to wheel setups, it’s important to understand what performance targets are important for the operation. Both setups provide users with various benefits. Wheeled tractors have a lower initial purchase price and lower operation cost. When the wheel tractor is set up with tires that allow for inflation pressures below 15 psi, the wheel tractor will have lower soil contact pressure versus a tracked tractor. In wet soils, a tracked tractor provided better traction performance, because the track acts like a road paver. As the tread of the track engages the soil, it stays in the same position, and the undercarriage moves forward. That is why a tracked tractor does not seem to rut the field up in wet conditions. On a wheeled tractor, the tire is continuously rotating, and in wet soils, the tire pushes the soil, causing ruts.

It doesn’t matter whether a 620 hp tractor has tires or tracks; if the tractor does not seem to have the proper traction in the field, the first step is always to make sure the tractor is ballasted correctly. After the ballast has been corrected on wheeled machines, make sure the inflation pressure is set to match the axle loads; and on tracked machines, make sure the undercarriage tension pressures are correct. If more traction is needed on a wheeled tractor, IF and VF tires will provide a larger footprint, which generates more traction in the field, and could be a lower-cost solution versus purchasing a tracked machine. If the machine is going to be used in wet conditions, a tracked machine may be a better option, but remember that the track machine is still compacting the soil.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

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James Tuschner <![CDATA[Best Load Speed Index]]> https://agtiretalk.com/?p=1438 2019-07-02T13:06:21Z 2019-07-02T13:06:21Z How does producer choose best Load Speed Index, what is impact of IF / VF, and how does change from transport speed to in field affect air pressure requirements?

Continental Agriculture North America
Harm-Hendrik Lange: Agriculture Tires Field Engineer

Starting with the simplest component: Speed Symbol (SSY). The Speed Symbol is the maximum speed the tire is designed for. It correlates with Load Index as a STANDARD TIRE can carry even more if the speed is lower. For Agriculture Radial Tires, the most common Speed Symbols are A8/25mph, B/31 mph, and D/40 mph. If your tractor runs faster than 25 mph, you will need the B or D rating. If your tractor is 25 mph or lower, A8 is fine.

STANDARD TIRES

A little more complicated is the Load Index (LI): it is always related to a certain speed and to the (nominal) inflation pressure.

Here’s a practical example for a 710/70 R42:

The tire is rated with 173 D, so it can carry 14,330 lbs at 40 mph.

If you have a tractor with a max speed of 25 mph, the load can be increased going down three SSY (D=>C=>B=>A8).

This allows you to increase the LI three steps meaning the 173 D tire becomes a 176 A8 tire and can now carry 15,652 lbs at 25 mph.

The third influence on standard tires is the inflation pressure. Higher inflation pressure means higher load capacity. Therefore, the maximum LI and SSY are always given at the maximum allowed inflation pressure at maximum speed, called nominal pressure.

A farmer who is aware of the soil and its effect on plants, should choose a tire by its ability to be operated with low inflation pressure on the field instead of looking at the maximum LI and SSY for road conditions.

As shown above, the contact patch is directly affected by tire load and the inflation pressure. Adding load to the tire will increase the contact patch, while the pressure stays constant in this model. But also keeping the load constant and reducing the inflation pressure for in field will increase the contact patch.

In short, to run a STANDARD tire at maximum speed with a high load on-road requires a significantly higher inflation pressure, while you can reduce the inflation pressure at on-field speeds to protect the soil. All these pressure changes require technical solutions like an air pressure kit in the field, so a new tire model was evaluated.

IF / VF

The first step was the IF, and the second evolutionary step is the VF tire, taking out the need to change air pressure between field and road speeds at constant load and ~20% more load for the maximum specified speed for IF and ~40% more load at maximum speed point for VF at the same inflation pressure compared to a standard tire.

Overall:

The higher price for VF tires can be a good investment for farmers and contractors who change between field and fast road work often, as no pressure adjustment is needed for the different speeds with constant loads. VF enables you to ride up to the highest speeds with the lowest inflation pressures.

 

Precision Inflation, LLC
Ken Brodbeck, VP of Technology

First, be sure to have a speed rating that meets or exceeds the maximum speed of your machine.  Most radial tires are at least A8 (25 mph) or B (30 mph).  Newer technology tires are D (40 mph).

Next, be sure to have a load index that meets or exceeds the maximum weight requirements of your machine configured with implement you have chosen.

Your tire dealer and the major tire manufacturers list these values in their data books and online.  Now let me explain each term with an example.

Load Index: is a table of maximum load values that are standardized by the tire manufacturers.

Speed Index: is a table showing the maximum speed allowed for the tire.

The speed index is usually stamped on the tire sidewall right after the Load Index number.

How do Standard (St.), (IF) and (VF) tires compare at two different axle loads?

Summary:

  1. Without CTIS (Central Tire Inflation System), you have to run transport psi all the time
  2. IF and VF tires allow lower pressures of 19 and 16 psi respectively.
  3. WITH CTIS, a standard tire can be set for 14 psi in the field and 26+ psi on the road!
  4. Bottom line, often a standard tire with a CTIS can outperform the higher dollar IF and VF tires without an inflation system. See the above chart.

Inflation system technology also improves the performance of IF and VF tires.  In fact, every radial tire works better with CTIS to optimize and maximize the performance of your farm equipment.

 

Michelin Ag
David Graden: Operational Market Manager – Agriculture

On the sidewall you will find a load speed index expressed like this: 167B.

  • The first three numbers are the load indices or weight a tire can carry.
  • A8, B, or D indicates the speed rating of the tire.

Both weight carrying capacity and speed requirements must be assessed to choose the proper load speed index.

When determining speed requirements, I recommend both in field and transport maximums are determined.  Knowing physics enables a standard tire to carry load with significantly less air pressure at slower speeds, this is very important if you are concerned with reducing soil compaction.

For example, an 800/70R38 MachXBib carrying Max Load of 14,330 lbs. at 23 psi at 40 mph (transport) can carry same weight at 6 mph (field) with 15 psi.

Reducing pressure 8 psi over 5,000 acres equates to a significant improvement in a grower’s bottom line.

So how do you (real world) change air pressure from road transport to field quickly at crunch time?  Use a CTIS system.

Do you want to take air pressure savings to another level? IF / VF tires that can do even more.

In sum, determine required weight carrying capacity, determine in field and road transport speeds, and then I recommend investing in a Central Tire Inflation system.  To really maximize yield, go VF.

 

Alliance Tire Americas
James Crouch: National Product Manager—Agriculture

Load and speed index symbols are a little bit mysterious. The numbers—like 129, 141, 151—look arbitrary, and the use of stars or letter/number combinations like A8 to indicate load doesn’t feel very precise. But the most important aspect of load and speed index is that you know that they exist, and you make sure to match them to your needs when you purchase new tires.

Mysterious or not, load and speed index represent vital information. If you buy a tire with too low a load/speed index to cover your needs, you could overload your tire. That can lead to premature wear, accidents and spills, or even injury or death. I can’t say this too many times: you need to match the load and speed index of your tires to the machinery they will be running on.

Be sure to calculate your need for load and speed based on the real-world weight of each axle on your machine. That means you have to look beyond the machine’s shipping weight to also account for the weight of fuel, spray solution, ballast, and load on the drawbar. If it’s got a bucket on the front, add the weight of a full load of dirt or gravel. Be real about what you’re going to be doing with that machine and you will end up with an accurate load index.

The same goes for speed. The low speeds of planting or fieldwork can be accomplished at a lower inflation pressure than higher-speed road driving. If you’re going to operate a farm tire at higher speed, check your inflation tables to match the load, speed and optimum inflation pressure. If your pressure is too low for your load and speed, your sidewalls will flex too much and build up extra heat, which can result in excessive stress on the tire carcass and ultimately could destroy your tire.

That’s where IF and VF technology come in. The special design and materials in IF and VF sidewalls allow us to operate these high-tech tires at lower inflation pressure without giving up load and speed. In fact, the load rating of an IF tire at a particular inflation pressure is 20% higher than the load rating of a standard radial at the same pressure. With VF tires, the bonus load capacity is 40%.

To get the full benefit of IF or VF technology, check the inflation tables and make sure you run at the proper pressure for the load and speed that reflect your operating conditions.

And to really stay in step with load/speed index and optimum tire performance, central tire inflation system (CTIS) is the ultimate tool. Linking a compressor to each tire on the machine for on-the-go pressure adjustments, CTIS technology—used by the US military since the mid-’80s—is surprisingly affordable and allows you to increase inflation pressure to run safely on the road and decrease it for better performance and lower soil compaction in the field.

The nomenclature of load and speed index may be mysterious, but the answer to all the mysteries is right there on the inflation tables. Every tire manufacturer issues them for each of its tires, and here’s a link to standardized tables http://ataoffers.atgtire.com/tire-reference-tables  and you can find them online or in manufacturers’ literature. If you’re not sure how to read them, just ask your tire dealer to show you how.

 

Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

The Load Speed Index is the identification system that replaces the tire Ply Rating and the Star Rating. While there are a few key differences between these rating systems, utilizing the best Load Speed Index will lead to a better purchase when choosing the right tire for your operation.

The load index on tires indicates the load of the tire at the measured inflation pressure.

Quick tip: the specific load index value is equivalent to the rated load for any tire size.

For example, a tire with a load index of 168 equates to a rated load capacity of 12,300 lbs (5,600 Kg). Customers may switch from wide tires to narrow tires depending on the season and application. If you have a tractor that uses wide tires in the spring for planting, you may use a 710/70R42 168 tires on the rear axle, leaving each tire to carry 12,300 lbs at 23 psi.

The speed rating of the tire follows the load index, for ag tires is it usally A8, B, or D. A typical description would read 168 B. These values indicate the maximum speed the tires are recommended for.  The speed rating for each value is:

A8 = 25 mph (40 Km/H)

B = 30 mph (50 Km/H)

D = 40 mph (65 Km/H)

It is always important to make sure to match the maximum speed of the tire to the maximum speed rating of the tractor. In North America, the B speed rated tires will be acceptable for most tractors.  Currently, there are only a few tractors in the market which exceed 30 mph, but for those tractors the D speed rated tires are needed.

With the IF or VF technology in the tire, the load index value increases when comparing the same sized tires. The below tires are speed rated to 30 mph; however, the rated load increases with IF and VF technology (while maintaining a rated inflation of 35 psi):

  • 480/80R50 Standard Radial 159B
  • IF 480/80R50 166B
  • VF 480/80R50 171B

New tire technologies help customers by increasing  load capacity while maintaining the same tire size.

When setting inflation pressures in tires, the axle loads and the operating speeds are critical to ensure proper inflation. Without having a central tire inflation system (CTIS) on your tractor, the inflation pressure needed is based on the fastest travel speed and the maximum axle load. If the tractor is only being used to haul equipment, like a disc or field cultivator, there is not a weight difference between field application and road transport. Once the pressure is set, there is no need to adjust applications. If a tractor is being used with 2pt or 3pt equipment, the rear axle weight changes between field use and road travel. In this example, the inflation pressure of the rear tires would be set based on road axle weight and road travel speed. If the tractor does have a CTIS, the inflation pressure could be set for the field use and then changed for road transport.

Understanding load index and speed rating will allow you to make an educated decision when choosing your next set of ag tires.

If you have more questions, a certified Firestone Ag tire dealer can equip you with the right tires for your operation.

 

Maxam Tire International
Greg W. Gilland:  Business Development & Ag Segment Manager

Each Agricultural Operation requires equipment designed to maximize the harvest of that chosen crop.

In the case of Tractor applications, the choice of machine size and horsepower selected will dictate the size of tires that will be employed to deliver the planned or expected yield of crop.

Tires are the pressured vessel that create the interface between the machinery and the soil necessary to carry out the farming operation every step of the way from land preparation to crop harvest.

Agricultural tires are designed based on their size geometry, materials, and air chamber to carry a certain amount of weight at a given ground speed and to fit a certain wheel base or equipment.

All Radial Ag tires employ the tire carcass (rubber & nylon casing construction) to carry 20% of the given tire load with the compressed air in tire chamber carrying 80% of the remaining given weight.

The primary function of an Ag Tire is three-fold: u Carry the Load, v Resist Lateral Forces & w Transmit the Torque or Machine Power:

Ag tires are therefore rated by a common index to identify their load capability or carrying capacity at a given speed.

The key objective of any given machine utilizing tires in a farming operation is to choose the optimized air pressure that can carry the maximum weight expected, while providing the least amount of soil compaction.

The yield of the crops produced is directly impacted by the amount of ground pressure caused by the weight of the Ag Machinery due to the topical soil pressure or soil compaction caused by the equipment working in the field.

Growers should therefore choose the tire size and corresponding air pressure that best suits the weight and horsepower of their tractor as optimized to pull their heaviest implement in their operation.

The advent of “Increased Flexion” Technology or IF & VF Technology has revolutionized how the traditional tire is employed through the science of new rubbers and carcass materials able to carry additional weight at higher speeds or reduce soil compaction though decreased air pressure increasing the tire footprint for a given load.

  • IF Technology Tires allows either 20% more tire load at normal pressure or 20% less air pressure for the same tire load
  • VF Technology Tires allows either 40% more tire load at normal pressure or 40% less air pressure for the same tire load

  • The advantage of IF & VF Technology is the capability to reduce soil compaction with lower air pressure by extending the tire footprint or conversely the ability to carry more weight at the same ground pressure or standard air pressure.

To maximize the utilization of IF & VF Technology tires, the Grower should consider adjusting the air pressure of his tires as he modifies the weight being pulled or load being carried by his equipment. The optimal air pressure in every case will reduce the ground pressure thus increasing the yield of crops through reduced soil compaction.

Higher transport or road speeds will demand higher air pressure to sustain the weight and/or corresponding speed to move Ag equipment from the barn to field operation or from field to field. Newer tractor and Ag equipment are utilizing onboard inflation equipment to quickly adjust IF or VF Tires up or down in air pressure to the optimal footprint needed to either move on the road or in the field.

The challenge to the Grower is to employ sustainable methods to adjust and maintain the air pressure of his IF or VF Tires as he moves his equipment from transport mode to field working mode by lowering the air pressure to the absolute minimum needed to float over the soil thus reducing compaction while transmitting the necessary torque or force to pull his equipment and get the job done. The Right Air Pressure for the Right Load is the answer to improved Ag Profits.

 

Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

Lets first clarify what Load Speed Index means. In modern tire manufacturing each tire has a specific Load Index (LI) and a Speed Symbol (SS) and both together are referred as Load Speed Index. The Load Index (LI) represents the load capacity at the nominal inflation pressure of the tire and there is a direct correlation between load capacity and inflation pressure (the higher the inflation pressure, the higher the load capacity).

These values depend on the tire size (width, ratio and rim diameter) and are all normalized by TRA (Tire and Rim Association) in the US and by ETRTO (TRA counterpart in Europe) meaning that a specific tire size, at a specific inflation pressure will have the same Load Index (LI) for all tire manufacturer (comparable apples to apples).  If for the same tire size, the market offers different Load Index values, it means their nominal inflation pressure (highest inflation pressure allowed) is different. For example, for a Mitas 1250/50R32 SFT 188A8 the nominal pressure is 35 psi (2.4 bar) and for Mitas 1250/50R32 SFT 194A8 the nominal pressure is 47 psi (3.2 bar). Each manufacturer tire catalog will include the table specifying the load capacity for each Load Index (LI).

On the other hand, the Speed Symbol (SS) represent at what speed this Load Index (LI) is referred to. A large combine flotation tire will normally have a A8 Speed Symbol (SS) that represent 25 mph (40 km/h). On a sprayer specific tire, the Speed Symbol (SS) will be a D representing 40 mph (65 km/h).  On conventional tires the reduction of working speed allows higher load capacities of the tire. This can be explained in the fact that at higher loads the tire temperature increases, and the temperature increases also when the speed is increased. So, when we reduce the speed (lower temperature) we compensate for the temperature increase by increasing the load. For example, a Mitas 480/80R50 159A8 inflated at 2.4 bar will be able to carry 9,650 lbs. (4,375 kg) at 25 mph (40 km/h) and 13,500 lbs. (6,125 kg) at 6 mph (10 km/h)

Standard Tires

When looking into a tire manufacturer manual, you will see that for each conventional (non-IF or VF models) tire size there is a specific data matrix with inflation pressure and speed. Each combination (inflation pressure vs. speed) will specify the max load capacity of that tire for this combination. So, when farmer wants to know what inflation pressure he needs for his tires, first he must know the load each tire has to hold and second the speed he will be using for that load. With these two values he can determine the correct inflation pressure for his tire. It is very important to use the correct inflation pressure depending upon the load applied and the speed used as this will allow to have the best performance and the largest footprint (lower compaction) of the tire. An over-inflated tire will result in a higher soil compaction.

IF / VF Technology

When talking about newer and higher tire technology, we must talk about IF (Increased Flexion) and VF (Very High Flexion) type tires. Both technologies represent reinforced tires that allow higher load capacities (20% higher for IF and 40% higher for VF) at the same inflation pressure for the same tire size, compared to conventional tires. Using this same concept, we can say that if we have the same load applied to the tire an IF tire allows to use 20% less inflation pressure and the VF 40% less inflation pressure (always comparing same tire size). For example, comparing the load capacity between the conventional Mitas 710/70R42 173D SFT vs. the VF version Mitas VF 710/70R42 179D HC2000 at 23 psi (1.6 bar), the conventional can carry 12,350 lbs. (5,600 kg) and the VF can carry 17,085 lbs. (7,750 kg). On the other hand, if our tire needs to carry 12,350 lbs. (5,600 kg) the conventional tire would need 23 psi (1.6 bar) and the VF tire would require 14 psi (1.0 bar) for the same load. This reduction in inflation pressure will increase the total footprint and reduce the specific pressure on the soil and the soil compaction.

These higher technologies have the special characteristic that the load capacity will not change by changing the speed only by changing inflation pressure. Making it easier for the farmer to adjust the correct inflation pressure.

 

BKT USA, Inc.
Dave Paulk: Manager Field Technical Services

Speed and load ratings on tires have become more important with the influx of tractors and equipment coming into the U.S. from Europe.  When choosing a tire, weight carrying capacity for the weight of the tractor, the intended load, and the transportation speed should all be considered. Some tractors will run up to 45 mph, so the tires must be able to carry the weight required at those speeds.

The load and speed index of a tire follows the size on the sidewall of the tire. Charts are available to show the maximum load capacity of a radial tire at the maximum speed. The charts can be found in most tire manufacturers’ handbooks, as well as on the internet.  An example is a tire may have a 154D/157A8 Load and Speed Index rating (BKT 600/65R38 RT 657). This means that the tire will carry 8,250 lbs. (154 load index) at 40 mph (D speed rating) at 35 psi. This same tire will carry 9,090 lbs. (157 load index) at 25 mph (A8 speed rating) at 35 psi. The higher the speed, the less weight carrying capacity a tire can handle.

Tires that come on Original Equipment tractors are selected by equipment manufacturers to carry the loads of the tractors with ballast to handle the speeds that modern tractors run. Aftermarket add-on’s (ex. saddle tanks) sometimes cause overloading on the tires, usually the fronts, and will cause the tires to fail prematurely. The rears can also be overloaded with the heavier equipment, so correct air pressures are vital to prevent premature failures.

Radial farm tires are designed to run at lower air pressures in the field, at field speeds (5-10 mph). The higher the speed, the less weight carrying capacity a tire has. 8-10 psi may be perfect at field speeds, but when the tractor is transported between fields and/or farms on the highway at 30 mph, the weight carrying capacity is greatly diminished. The tires may need more air pressure to transport equipment on the highway than they do in the fields. Sidewall damage and sidewall separations can occur when tires are run overloaded and under inflated. Realizing that time is precious in the spring and fall during planting and harvest, money can be saved by running the correct air pressures for the application and usage during these times.  Air Inflation Systems are now being offered as aftermarket items, but manufacturers are looking at them as OE options to minimize tire damage and premature failures.

IF and VF technology is being used to enable a tractor to carry more weight without having to widen the tire to the point where it can’t be transported on the highway. This technology can also be used to reduce air pressure to minimize soil compaction in areas where no till and minimum till is used. An IF rated tire will carry 20% more weight at the same air pressure as a standard tire of the same size. A VF rated tire will carry 40% more weight at the same air pressure as a standard tire of the same size. If an IF/VF tire is being used, air pressure can be reduced to carry the same weight as a standard tire. This decreases ground bearing pressure, and thus reduces soil compaction. On the opposite side of the spectrum, sometimes the higher weight carrying capacity is needed. An example is radial implements (IF rated) on planters and cultivators where a bias ply implement tire will not carry the heavy weight of the implements. The VF rated tire is good for sprayers as they run at higher speeds and can handle the weight capacities.

There are still a huge number of bias ply farm tires running in the U.S. market. Bias ply farm tires are designated with ply ratings. The higher the ply rating of a bias farm tire, the more air pressure it holds and the more weight it carries. Bias ply tires, unlike radial farm tires, are not made to run at low air pressures. If bias tires are being used, the load carrying capacity should be checked to make sure they are not being overloaded.

It is important to consider many things when choosing the correct tire for your equipment, your load, and your fields.  BKT technological specialists are available to help with any questions you may have.

 

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

Before I get started, I think it would beneficial to review the differences in tire technologies and what they offer.

  • Conventional tires are just that, they have been around since the dawn of the pneumatic tire.
  • IF (Increased Flexion) tires are designed to carry the same load at 20% less inflation pressure than the conventional tire of the same size.
  • VF (Very High Flexion) tires are designed to carry the same load at 40% less inflation pressure than the conventional tire of the same size.

The theory behind IF_VF technology is that as the tire deflects more the footprint becomes larger and the larger footprint means less ground bearing pressure and ultimately less compaction

With so many tire options it can be a bit confusing when making decisions on what one should purchase.  Tractor manufacturers offer a multitude of options.  They actually do a good job of offering the appropriate load and speed index tires on the tractor coming out of the factory.  If a grower is in need of replacement my quick answer is to replace it with a similar rated tire, you really can’t go wrong.

Things get a bit more complicated if that grower is attempting to make a tire technology change which requires a bit more thought.  For instance if they are looking at converting a MFWD from conventional tire technology to IF_VF technology not only will they need to replace all of the tires on the tractor they will need to choose a load index that suits the tractor at its heaviest condition.  Some manufacturers take into account that at slower speeds conventional tires are actually allowed a load bonus or plus up at 20 mph (+7%), 15 mph(+11%) and 10 mph(+34%) as it operates in at different speeds.  See Table 1

Table 1

In this case a 154 load index rated at 8250 lbs. at 23 psi is capable of carrying 11055 lbs. under 10 mph.  When converting to IF or VF there is no load bonus for slower non-cyclical applications.  An IF or VF tire can carry the same load at 40 mph as it does at 10 mph but is not allowed a load bonus or plus ups.  That means that you will need to select a load index that will cover at least as much of the load of the standard tire to meet the load requirements of the tire you are taking off.  See Table 2

In this case the tractor would need to be converted to 165 load index and that tire would need to be inflated to 32 psi in order to carry the same load.  Now granted a tractor typically doesn’t see those extreme loads all the time and inflation pressures can be adjusted much lower for general farming, but it is important that you select a tire with a load index high enough to handle those times when the tractor is experiencing those conditions or you will risk damage and or failure to the tire and possibly damage the tractor.

At the end of the day the grower needs to decide what is best for their operation.  Converting to new technology on an existing tractor is not cheap and they need to weigh the benefits vs the cost.  But if they do decide, it is best they understand the technologies and what gets them the biggest bang for the buck. In addition, doing research and understanding their loads and applications will give them the best chance of being successful with the conversion.  The tire dealer or tire manufacturers would be a great resource to ask questions if they are having trouble understanding.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

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James Tuschner <![CDATA[Warranty Stop]]> https://agtiretalk.com/?p=1368 2019-05-01T01:50:27Z 2019-04-30T15:26:05Z Welcome to AG Tire Talk’s new Warranty Stop Page!

We made it easy for you, posting all the AG Tire Manufacturer’s Warranties in ONE place- with a Radial R-1/R-1W Summary of each.

 

TITAN / GOODYEAR WARRANTY SUMMARY

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

You could spend hours comparing each and every aspect of every tire company’s warranty policy.  Stubble, Field Hazard, Workmanship and Materials along with the length of the warranty, and how it applies with respect to how the amount of credit is determined based on years of service or wear are all factors to consider.

One of the first things a producer should look for to maximize return on investment with warranty is to make sure they have a local servicing dealer that can handle the claim.  Titan/Goodyear has one of the most extensive dealer networks in North America.  That means in almost every rural area the producer can find someone not only to handle his tire requirements but also administer warranty claims when they come up, making the warranty claim easy and hassle free.  You can confirm a Titan Goodyear dealer is near you by clicking  https://www.titan-intl.com/dealer-locator

On Manufacturer Defect Warranty, you should make sure No Charge Free Replacement includes Service and Labor charges, as this can dramatically reduce the cost for a producer if there happens to be an issue.  The initial length of time for “No Charge” replacement due to workmanship issues and on what types of tires is extremely important to know also.

On Stubble Protection Warranty, make sure your Radial Rear is covered before you purchase, as many manufacturers only cover “stubble branded” tires. Some manufacturers require a knock down device be installed after the 1st warranty claim.  That is actually money very well spent any time when you install new tires especially for stubble damage.  Front tires on tractors are changed 3-1 compared to the rear tires.  Common sense tells you it’s because the front tires are knocking down the stubble, so it only makes sense if you put a mechanical device in front, you could actually be tripling the life of the tires.  That is really maximizing your return on invest.

A Warranty Policy is one of many factors a person considers when they are making a tire purchase.  I think the decision to purchase a particular brand is based more on the end users experience with that brand and more importantly how their particular tire dealer services him than it has to do with an actual warranty policy itself.  We all want to do business with people you trust and who treat you fairly.  I don’t think any tire company is intentionally trying to put poor quality product into the field. But if there is an issue, that is where the relationship between the customer and the tire dealer, and then the tire dealer with the manufacturer becomes so important.

Titan is the only company with a team of Ag Specialists in the field whose sole purpose is to assist tire dealers and end users with issues regarding tire application and machine set up to maximize their performance in the field, and also avoid costly downtime due to an unnecessary warranty claim due to misapplication or wrong inflation pressures.  At Titan I like to think we have the end users covered on every aspect of their ownership of a Titan/Goodyear product.

TITAN / GOODYEAR FULL WARRANTY  https://www.titan-intl.com/warranty

 

ALLIANCE WARRANTY SUMMARY

Alliance Tire Americas
James Crouch: National Product Manager—Agriculture

Radial R-1 and R-1W tires are the mainstay of the ag tire market, and they are the work horses of the farm. Investing in a high-quality R-1 or R-1W tire is one of the most productive things you can do to keep your tractor or combine working effectively and efficiently.

But sometimes, things happen. A corn stalk punctures a shoulder, stubble picks away at the tread until air is lost, or some sort of unusual manufacturing defect causes a tire to fail. That’s when a good warranty makes a big difference to your business.

When you shop for a tire, ask your dealer about the warranty that covers it. Of course, the first thing that should jump out is the length of the coverage. Obviously, the company is not expecting many failures during the warranty period, so if they’re willing to back a tire for many years of service, you can figure it’s a very safe bet. When a manufacturer promises long warranty coverage—6 or 8 or even 10 years—it’s making a very strong statement about the quality of its tires.

Look for Stubble Damage, Field Hazard and Manufacturers’ Defect coverage, of course. Consider problems you’ve had over the years, and make sure the warranty would cover them, or that you at least know what’s not covered.

But just as important as the warranty policy is how easy it is to handle a claim. Is there a lot of paperwork, or can the process be handled smoothly? Do you have to haul the tire into town, or can you just send a few pictures from your phone?

Also, be sure to ask your dealer: does this company handle warranty claims quickly and smoothly? Do they have your back? After all, a warranty is just a bunch of legal language until a company makes good on it.

That’s why we’re so proud of our ATG Warranty Wizard app. It’s a smartphone app for iPhones or Androids that makes a warranty claim really simple to file—it walks you through a few questions, you take a few photos with your smartphone and push “send.” The information goes directly to the people who need it to process your claim, and they handle each claim promptly. It’s as simple as that.

As for Alliance Tire’s warranty terms, our new farm tire warranty is one of the best in the industry. Here are some highlights:

  • Steel-belted Ag Radials: 10 years of wear coverage
  • Non-steel-belted Ag Radials: 7 years of wear coverage
  • And we still have our great, 3-year stubble damage and field hazard policy for qualifying Ag tires

Tires worn less than 25% and deemed in “adjustable condition” will be replaced without charge (excluding mounting and service charges). Tires with more than 25% wear deemed to be in adjustable condition will be prorated based on the remaining tread depth. Details and the full ATG warranty policy are available online at https://atgtire.com/usa/atg-warranty-policy/.

Here’s the bottom line: a warranty is an important tool and a major consideration when buying a tire—and so is the company that’s backing it.

ALLIANCE FULL WARRANTY: https://atgtire.com/usa/atg-warranty-policy/

 

BKT WARRANTY SUMMARY

BKT USA, Inc.
Dave Paulk: Manager Field Technical Services

Agricultural tire warranties should be an important consideration when buying tires. Most all manufacturers have a Limited Manufacturer’s Material and Workmanship Warranty. The time and conditions of the warranties vary from manufacturer to manufacturer.

No matter how well a tire is made, there is always a risk that a tire may become unserviceable due to the conditions it is used in. A warranty provides protection should a customer have issues with a tire due to a manufacturer defect or material related failure. There are steps to prevent the possibility of tire failure.  Running the correct air pressures and loads diminish the chances of having to adjust a tire under these circumstances and conditions.

Some companies offer a Field Hazard and Stubble Damage Warranty, comparable to the Road Hazard Warranty on automobile and light truck tires. The Field Hazard part of this warranty covers tires that become unserviceable due to non-manufacturer related circumstances. This can be the most important part of the warranty to help a farmer protect their investment with circumstances that they sometimes can’t control.

Stubble Damage, the second part of this warranty, is caused by corn, cotton, soybean, etc. stubble penetrating the tire and causing air loss. With most manufacturer’s warranties, the tires must be unserviceable and not able to be repaired to be adjusted under this provision.  To minimize stubble damage, mount equipment to the front of the tractor to push the stubble over to eliminate stubble penetration into the tire. Also, if possible, cut the stalks taller so the front tires push stubble over instead of directly running over it helps.  Tires are made of rubber and fabric and unfortunately aren’t indestructible. This is an important part of the warranty of help a farmer protect their investment of tires.

BKT has a both a Limited Material and Workmanship Warranty and a Field Hazard and Stubble Damage Warranty to help farmers protect their investment by purchasing BKT agricultural tires.

BKT’s Limited Material and Workmanship warranty covers Radial agricultural tires for 9 (nine) years from the date of purchase or the date of manufacture if proof of purchase cannot be furnished. This will cover any condition considered to be a manufacturing defect by BKT.

BKT’s Limited Material and Workmanship warranty covers Bias agricultural tires for 3 (three) years from the date of purchase or the date of manufacture if proof of purchase cannot be furnished. This will cover any condition considered to be a manufacturing defect by BKT.

BKT has a 3 (three) year Radial Field Hazard and Stubble Damage Warranty from the date of purchase or date of manufacture if proof of purchase cannot be furnished. This covers both for a period of 3 (three) years. The tire must be unrepairable to be considered for warranty under this provision.

BKT has a 1 (one) year Bias Field Hazard and Stubble Damage Warranty. This is determined from the date of purchase or date of manufacture if proof of purchase cannot be furnished. The tire must be unrepairable to be considered for warranty under this provision.

There are tables in BKT’s warranty to determine warranty amounts for both the Material and Workmanship Warranty and the Field Hazard and Stubble Damage Warranty.  They are based on time in service and tread wear.

BKT FULL WARRANTY:  BKT Warranty

 

CONTINENTAL WARRANTY SUMMARY

Continental Agriculture North America
Dana Berger, OE Sales Representative and Farm Project Lead

Continental released their 10-year Agriculture Tire Warranty for the United States and Canada in February 2019. When discussing what we could offer farmers, one of the first suggestions was to re-enter the market with an industry leading warranty length. Why not extend our confidence in our new products by offering a 10-year warranty? We wanted to focus more on what the farmer needs from a tire supplier – so we did.

With today’s crops increasing their strength against the elements and maximizing their yield for our ever-growing populations, tire manufacturers are faced with constant challenges. Continental is facing those challenges with new technologies, like our N.flex carcass and single wire bead along with one of the best warranty programs on the market.

Some farmers will hold on to a tractor for the entire length of its life. For those farmers, the extended support from a tire supplier proves that we value their hard work. On the other hand, farmers who lease their equipment will benefit greatly from our Stubble Damage and Field Hazard coverage. This comes back to the density of the stalks causing tire damage. With the proper stalk dampening procedures in place, a farmer can be confident that Continental will stand behind them, should there be damage from regular operation. This includes any concerns from piercing or blowout situations related to field hazards.

Tires are an investment for a farmer. Even leased equipment must often be returned with a tire in good condition within reasonable treadwear use. For a R-1 and R-1W tire, the farmer needs to consider the tread depth and overall wear when they turn in their equipment. Our warranty can help the farmer not have to purchase a full priced tire that they won’t benefit from, upon return. If they need to replace a tire from workmanship and materials, field hazard or stubble damage, we will prorate the remaining tread depth percentage with a credit toward a new Continental R-1W tire.

Ultimately, a warranty is all about the customer. Continental’s Radial Agriculture Tires are “Engineered for Efficiency” on the farm. We look forward to joining some of the country’s hardest working professionals in the field.

Basic Coverage Summary:

Any tire that becomes unserviceable from a covered warranty condition will be repaired or a pro-rata credit will be issued towards replacement with a new Continental or General Tire brand tire. This credit will be determined by applying the lesser of the percentage of actual remaining tread depth (RTD%) of the covered tire, or the maximum credit based on the age (from purchase date) of the covered tire as indicated in the attached chart.

Stubble Damage Coverage:

If, in normal agricultural service, a covered tire becomes unusable or not repairable due to Stubble Damage (piercing or erosion due to plants and/or crops), a pro-rata credit will be issued towards replacement with a new Continental a pro rata basis based on the purchaser’s then current (at the time of adjustment) purchase price for the covered tire. The first year has 75% pro-rata credit, the second year has 50% pro-rata credit, and the third year has 25% pro-rata credit.

In order to qualify for Stubble Damage Coverage, the owner-user must use reasonable efforts to reduce Stubble Damage such as adjusting tire spacing to run amid the crop rows, knocking down stubble with the help of mechanical devices readily available through equipment manufacturers, and running parallel to the rows for the first tillage pass.

Field Hazard Coverage:

If, in normal agricultural service, a covered tire becomes unusable or not repairable due to Field Hazard Damage (piercing or blowouts due to hazards commonly encountered in agriculture field settings),a pro-rata credit will be issued towards replacement with a new Continental a pro rata basis based on the purchaser’s then current (at the time of adjustment) purchase price for the covered tire. The first year has 50% pro-rata credit and the second year has 25% pro-rata credit.

CONTINENTAL FULL WARRANTY: Continental General Warranty

 

FIRESTONE WARRANTY SUMMARY

Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

When purchasing new equipment or new tires for your current equipment, does the tire manufacturer’s warranty or policies factor into your decision? Does your tire dealer or equipment dealership help you understand the warranty that comes with your purchase? What is the difference between a warranty and policy, and what should you ask your dealers when comparing the warranties or policies?

The Firestone Ag manufacturer’s warranty is a program in place to help customers when the tire becomes unusable for any reason within the manufacturer’s control. The manufacturer’s warranty applies when the customer uses the tire correctly, but it becomes unusable. In Firestone’s published manufacturer’s warranty, there are examples of what typically is not covered under the manufacturer’s warranty, like tire damage due to apparent overloading, abuse of the tire, rapid tire wear, mounting damage or improper repairs. The list of typical conditions not covered is in the Firestone manufacturer’s warranty, which can be found at FirestoneAg.com.

Firestone agricultural radial tires (excludes Performer EVO–branded radials) have a manufacturer’s warranty of nine years and six years for the Performer EVO–branded radial and bias tires. The Firestone manufacturer’s warranty start date is based on the tire or new equipment’s original proof of purchase (POP) date. If the POP is lost, Firestone will use the DOT serial date code of the tire to determine the age of the tire. This serial date code is found on the sidewall of the tire, and shows the week and year the tire was produced. The published manufacturer’s warranty outlines the amount the customer pays, based on the age of the tire. The Firestone warranty is transferable between owners of the equipment, which means it doesn’t matter if you’re the first, second or third owner — the Firestone manufacturer’s warranty stays with the tire.

Firestone Ag also provides a Stubble Damage Policy and/or a Field Hazard Policy on R-1 and R-1W tires. A policy is extra protection that extends to the customer when the customer follows all the recommended operating instructions, but damages a tire early in its life. The  Field Hazard and Stubble policies are there to help customers when  a tire is damaged beyond repair and the damage is not within the tire manufacture’s control. Firestone’s Stubble Damage policy is a three-year program, and the Firestone Field Hazard policy is a two-year program. Unlike the manufacturer’s warranty, the policies only apply to the original owner of the tire. Just like the warranty, Firestone will use the proof of purchase as the start date of the policy. The published Firestone policies can be found at FirestoneAg.com, with a full explanation of what is covered and the common limitations of the policy.

The questions to ask your dealer when comparing the manufacturer’s warranty or policy:

  • Do these tires have a manufacturer’s warranty or policy?
  • Where can I find the published manufacturer’s warranty or policy?
  • How many years are the tires covered under the manufacturer’s warranty?
  • How much do I need to pay if there is a warranty or policy claim?
  • Is the labor or service call covered by the manufacturer?
  • Does the warranty or policy transfer to the next owner?

Asking these questions is a great way to understand the total purchase price of the tires. A certified Firestone agricultural tire dealer will be able to walk you through the warranty that comes with every Firestone agricultural tire. If you have additional questions or want to do some initial research, you can read and print Firestone’s warranty and policies at Firestone Warranty

FIRESTONE FULL WARRANTY  Firestone Warranty

 

TRELLEBORG / MITAS WARRANTY SUMMARY

Warranty is a word that should symbolize manufacturing quality and the compromise of the tire manufacturer to stand behind his product with high quality and after sales support. This compromise must be complemented with the local tire dealer knowledge and support. This combination assures that the final tire customer has peace of mind.

There are several aspects to consider when analyzing tire manufacturer warranties and how its applied in each case. Several steps must be followed in order to have a hassle-free process in case a warranty has to be used. Always the process starts with your local tire dealer and he will determine if the issue is warrantable and will follow up the process with the tire manufacturer. If your local tire dealers do not respond to your expectations, most tire manufacturers offer a toll-free number to contact them. Please don’t abuse this resource and use it only as the last resource.

First point to consider is the length of the covered period, when it starts, how the credit is applied in case the warranty is accepted, paperwork required and what additional perks the tire manufacturer offers. For most cases, especially with well-known brands warranty coverage period starts when the tire is sold to his final user. For example, a farmer that bought a tractor, the start of his warranty is the date of the tractor invoice – it’s important to keep a record and proof of purchase for a claim. If this information is not available, the start of the warranty is the date of manufacturing of the tire (date code) stamped on the tire – normally 4 digits representing the week and year of manufacturing.

Claim type. The tire manufacturer warranty covers – during the covered period – for defects in material and/or manufacturing. The tire must be used as its designed to be used, the warranty will not cover for improper use, maintenance, storage and/or abuse of the tire. Cosmetic blemishes – as small stubble damage – that will not affect the tire performance are not warrantable cases. Always consult with your local tire dealer if your situation is covered by the tire manufacturer warranty before starting a claim. In the case the tire dealer agrees on the viability of the claim, he is the responsible to collect all the information and evidence of the claim and submit it to the tire manufacturer for analysis. Even in this case, always wait for final manufacturer approval of the claim.

Type and quantity of the adjustment from the tire manufacturer. This criterion defers between manufacturers and most apply a percentage of reduction per year. For example, in a 5-year warranty, the adjusted credit will be reduced by 20% for each year of usage (a 3-year-old tire would get a 40% credit). For Mitas tires, the credit is based on remaining tread depth at the time of the claim (takes in account the tire usage). So, if a tire is 6 years old and the tread dept is 50% of the original, the credit would be of 50%. Once the claim has been accepted by the tire manufacturer, the credit will be issued to the local tire dealer that initiated the claim and forwarded to the end customer. In most cases the credit is applied toward the purchase of the replacement tire.

Some tire manufacturers add additional perks to their warranty. Mitas added to the warranty what is called a Field Hazard for the first 3 years of covered warranty, independent from any manufacturing or material defect. This perk applies when a tire suffers a damage beyond repair (puncture by deer antler for example), where the tire functionality is compromised, and the tire has not been misused. In this case Mitas will help the final tire owner with part of the replacement tire cost proportional to the length in service.

Another policy to consider when purchasing an agricultural tires is related to Stubble Damage. Some manufacturers include this policy in their warranty, be sure to ask for the Stubble Damage policy and review it with your tire dealer.

It is important to operate tire within the load and speed limits at the air pressures specified by manufacturer according to individual tires size, type, and load capacity and to maintain proper alignment of wheels, avoid overloading and any other misusage of the tires. (Read the owner-users obligations in the warranty manual).

As a final consideration always remember to follow owner’s obligations, perform preventive maintenance and rely on a professional tire dealer. Tire manufacturer support and response is key to the success of an operation. A long warranty period is no good if the dealer is not supportive or there are two many clauses excluding the warranty. Always review all the requirements of the warranty.

MITAS FULL WARRANTY:  Mitas Warranty

TRELLEBORG FULL WARRANTY:  Trelleborg Warranty

 

CEAT WARRANTY SUMMARY

CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

Growers who are looking to purchase radial Ag tires should start the process by identifying the product or products that best fit their needs. After a grower identifies one or more candidates, they should gather information on costs, availability, past experience and inventory. It may be prudent to check these items with several dealers. The warranty policy should also be a big part of your fact-finding process. The warranty coverage may be a determining factor in your purchase.

CEAT’s FARMAX brand Ag radial tires are covered by a limited Ag radial warranty that provides seven years of Workmanship / Materials coverage. If the tire becomes unserviceable, unrepairable or unsafe during the first seven years in service due to a Workmanship / Materials defect, the original owner is covered by this seven-year warranty. During the first two years, there is a No Cost Replacement as long as the tread depths are at 75% of the original tread depth or more. Credits for years three through seven are pro-rated on a tread removal basis.

CEAT also offers a Field Hazard / Stubble Damage warranty for a three-year period on all CEAT Ag tires. If the tire fails or is unrepairable during the first three years in service the grower has coverage at a 75% level for the first year, 50% during the second year and 25% coverage during the third year.

Time in service for warranty calculations is based on dealer invoice to grower. If the invoice is not available, the fallback position is the date code molded on the sidewall. CEAT is not responsible for any associated costs or damages caused due to the failure or the replacement process.

Please see the complete warranty policy for all details of CEAT’s FARMAX Ag radial warranty.

CEAT FULL WARRANTY:  CEAT Warranty

 

MAXAM WARRANTY SUMMARY

Maxam Tire International

Greg W. Gilland:  Business Development & Ag Segment Manager

A Grower should first and foremost find Ag tires that meet his definition of “Value” for his Farm, Ranch or Operation. Our Maxam Agrixtra Family of Radial R-1W Ag tires are designed to deliver the best possible “Value” to a Grower through superior traction, ride comfort, and endurance at a competitive price. Our New Ag Warranty was developed to ensure we give that same grower “peace of mind” in his purchase of Maxam Radial Ag Tires by protecting his investment.

The protection we provide for our Radial Product Line Workmanship & Materials is Eight (8) Years, with a Two (2) year Free Replacement <25% of wear that includes standardized labor and service reimbursement.  After free replacement time frame, our Workmanship & Materials warranty is based on years of service only, not tread depth.

Maxam also offers both Field Hazard & Stubble Damage protection with Four (4) years of coverage, based on both years of service and tread depth.

Lastly, we offer Four (4) year Workmanship & Materials warranty for scraper service, in addition to the above Agricultural service coverage noted.

See the details of our coverage by clicking the link for 2019 Maxam Ag Warranty Brochure, or as noted in the below Summary Table:

MAXAM FULL WARRANTY: Maxam Warranty

 

MICHELIN WARRANTY SUMMARY

Michelin Ag
David Graden: Operational Market Manager – Agriculture

No one really wants to spend their valuable time sending in warranty claims for their tires. The fact is, in the case of Ag tires, most warranties tend to cost you. Typically, when a warranty claim is filed, you end up paying for the rubber/time used on that tire; not to mention the down time, mounting, labor etc. A typical comment I hear is, “That’s why I paid so much for this tire to begin with!”

Good point, however, regardless of whom the tire manufacturer is, there will be occasional manufacturing issues that cannot necessarily be controlled. For instance, folds in the rubber being extruded into the mold, shipping damage, delamination of one rubber compound to another, etc.

When choosing new Radial R-1/R-1W tires for your machine, it’s important to consider the warranty that comes with that tire. This warranty should not only protect you from Manufacturer Defects, but some will even protect you from possible damages caused by normal use.

For example, Michelin Agriculture tires come with a standard 9yr Workmanship and Materials warranty, where the first 2 years are No Charge to the customer including Service and Labor for replacement. After that, we start at 30%, 40%, and so on down to 9yrs.  It’s also important to know that Michelin credit is based on years of service only- not treadwear & years of service.

We also carry a 3yr Stubble Hazard warranty on all of our tires, with select “stubble shield” tires (YieldBib & MegaXBib2) having a 4yr warranty, again with Michelin credit based on years of service only- not treadwear & years of service.

To round out the total Michelin Agriculture Warranty offer, we also carry a scraper warranty, and if you wanted to try a set of Michelin Agriculture tires, we have a standard 90 day total satisfaction guarantee, where you can try the tires for a season and return them if they don’t work for you.

Bottom line, the environment in which agriculture tires work is severe. When you make your next purchase decision, it is very important to start with a quality product that will minimize downtime and additional cost down the road.  Lastly, it’s important to consider the entire warranty program. Not just one aspect.

MICHELIN FULL WARRANTY  Michelin Warranty

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James Tuschner <![CDATA[Preventative Tire Maintenance to Reduce Downtime]]> https://agtiretalk.com/?p=1313 2019-03-02T18:46:00Z 2019-03-02T18:46:00Z  

Alliance Tire Americas
James Crouch: National Product Manager—Agriculture

Tires are so durable in the field that it’s easy to forget that they can be damaged if they are stored incorrectly. The big hazards are letting them get out of shape and exposing the rubber compound to degradation.

The best way to store tires is standing up. If you stack them, be sure not to put smaller-diameter tires on the top of the pile—they can damage the sidewalls of the tires below them. A good rule is to avoid putting a tire on a stack that doesn’t cover most of the sidewall area of the tire below it.

If your tires are mounted when you store them, over-inflate them by 5 or 6 psi for storage to help them retain their shape over the off-season.

Rubber compounds are susceptible to damage from hydrocarbons, so keep them away from gas, diesel, oil, paint, solvents and mechanical fluids like hydraulic or brake fluid. They can also be weathered by exposure to UV, so keep stored tires out of direct sunlight.

Ozone can also degrade compound, so don’t store tires near electric motors, welders or transformers, which all create ozone as they operate.

As you get ready for the growing season, inspect your tires carefully. Make sure you don’t have any nails or other objects wedged into the tire (you’d be surprised what can have escaped your notice). Check sidewalls for blisters that indicate separation or impact damage, and for slashes or cuts that could threaten the integrity of the casing. Look over your tread for wear, chunking or cracks.

And, of course, adjust your inflation pressure to the proper level for the load and speed you will be operating at.

Invest in a tread depth gauge. They’re not expensive, and they’re easy to use. All you have to do is rest the feet of the gauge on your tread lugs or blocks and extend the probe into the space between the lugs. The key is to do it several times at different places in each tire. That way, you’ll pick up indications of uneven wear, which are important for determining whether your inflation pressure has been correct, and whether you need to rotate your tires more frequently.

Examining tread depth is important in determining whether your tires are worn out.

There’s no real, set number for when a farm tire is worn out. Obviously, if you see cords or damage, it’s time for a new tire. But there’s a little wiggle room on tire replacement based on what you expect that tire to do. If you’re counting on great traction to pull a disk or a planter, you’ll need some rubber on those lugs to get a good grip—same thing if you tend to run in muddy or slick conditions.

However, if the weather is dry or we’re just talking about a chore tractor that you use to pull a feed mixer or haul things around the yard, you might be able to squeeze an extra season out of a set of tires that are down to 20/32″ or so.

Think of it this way: if you just bought a thousand-dollar hunting rifle or a new drone, you’d make sure you took good care of it and stored it out of the weather. Your tires are worth that much or more. Treat them accordingly and you’ll be protecting your investment and setting yourself up for good performance this spring.

Continental Agriculture North America
Albert Sumera, Continental Commercial Specialty Tire Technical Solutions

As with any other tire that will not be used for a period of time, agriculture tires must be kept in clean, dry conditions and ventilated premises away from direct sunlight. They must be kept away from any source of ozone (for example an electric motor or transformer); away from chemicals, solvents, and hydrocarbons that may affect the nature of the rubber; and away from any objects that may pierce the rubber (sharp or pointed metal objects or tools). They should also be stored away from flames or hot objects.

Tires should be stacked if mounted, to avoid damage due to tension or compression. If mounted on a vehicle, de-ballast them as much as possible and over-inflate by 0.5 bar (7 psi) versus the operating air pressure used. Before the start of operations next season, check the physical condition of the tires and adjust to the correct operating air pressure.

Agriculture tires are normally used for a long period of time, however in instances when there is an observed substantial slippage (approximately more than 15%) depending on the surface of operation, the tires may be considered “worn out”. Being worn out is relative to where the machine and tires are being used and there is no general principle that can be applied to every situation.

Agriculture Tire Tread Depth Measurement:

  • Tread measurement should be made on properly mounted tires. Tires normally grow after first inflation. This effect is very significant the first few hours and can go on for the rest of tire life in minimal dimensions.
  • Recommendation for precise measurements at “new” condition:
    1. Set air pressure to 2.0-2.5 bar (29-36 psi) at mounting
    2. Run the tires for a few miles on road at max tractor speed
    3. Adjust the air pressure to the operating air pressure
    4. Measure the tread depth the next day (24 hours later)
  • Because of difficulty and variance in measurement of tread depth of agriculture tires, it is decided to use the center-line as the simplest measurement method.

1. Measure on four locations along the center-line of the tire (see image 2).

2. Use a flexible steel ruler to align with the round shape of the tire diameter by pressing the top of the ruler to the inside of lug 1 and the bottom of the ruler to the inside of lug 3 (see image 3). If a flexible steel ruler is not available, you can also use a hack saw blade.

3. Measure with a tire gauge down to the deepest point between lug 1 and 2 (see image 3).

4. We recommend measuring the tires every 500-1,000 hours, but the first measurement after fitment should be done earlier. During the first 100 hours the wear rate is generally higher (which is normal for all types of tires).

BKT USA, Inc.
Dave Paulk: Manager Field Technical Services

As spring tilling, spraying, and planting begins, farmers are reliant on good tires with minimal downtime. At this point of the year, downtime costs time and money- but before equipment is stored for the winter, there are things that can be done to minimize tire and equipment problems in the spring.

1. Tires should be checked for cracks, cuts, bulges, or any other type of visible damage. If there is any damage or possibility for failure, this gives time to replace or repair tires before they are needed again. Be sure to check tread depth. If the tire has less than 20-25% tread left, the tires may need to be replaced sometime during the next year. This gives the farmer time to budget for new tires.

There are several ways to measure tread depth. An OTR tread depth gauge can be used and bought through suppliers that cater to the tire business. Also, a straight edge with a ruler can also be used by laying the straight edge over the top of the lugs. Measure from the base of the tire to the straight edge with the ruler as close to the center of the tire as possible.

2. Make sure lug nuts are tightened to correct specifications. Check the bolts for wheel weights to ensure they are tight.

3. Inflate tires to the maximum recommended inflation pressure by the manufacturer for storage. Ambient air temperatures can cause air pressures to move up and down during the winter months when the equipment is not in use. Air pressures generally decrease in cold weather, causing the tires to go flat if they are not inflated enough. If tires go flat during the winter, the rim can damage the sidewalls by sitting on them. It is a good idea to check tires periodically while the equipment is stored to ensure they don’t go flat.

When taking the equipment out for use after storage, set air at correct recommended pressures to carry the weight of the tractor and equipment. This will ensure the tire is not damaged and will minimize soil compaction. Do not drive on flat tires.

4. Make sure tires are clean before storage. Clean the mud, sticks, and rocks from lugs and remove mud from the rim and weights (if wheel weights are used). In general, it is a good idea to store the equipment clean. When it is used again, it is ready to go.

5. If possible, it is best to store equipment inside in a cool and dry place. This keeps the sun, wind, rain, and snow from weathering the tractor and the tires. Ozone in the air and sunlight can cause rubber to age prematurely. It is best to keep rubber products away from electric motors, oils, fuels, and resins. If the tractor will be sitting for several months or more, it is best if the tires are not parked on rocks or asphalt. Rocks can damage tires if they lose air pressure. Also, asphalt is an oil-based material that will cause rubber to deteriorate over time. If the tractor must be left outside, cover the tires with a waterproof tarpaulin to avoid contact with ultra violet rays and bad weather.

There is really no cut and dried way to determine when it is time to replace tires based on tread depth. A tire that needs to be replaced in wet dirt may be fine in dry dirt. As tire lugs wear down, they can start slipping excessively which can increase fuel costs and time. Newer model tractors have wheel slip indicators where they should be in the 8-15% range, the closer to 8% the better. If the tire seems to be pushing dirt back behind it farther than normal, there is a good chance there is too much slippage. At this point, tires should be changed for optimal performance, and fuel and time savings.

All of these tips will help maximize tire life and minimize downtime.

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

Ag tires are designed to withstand the usage conditions of their respective application, but in order to achieve their full performance potential they must be maintained appropriately, which includes the condition in which they are stored in the off season in order to minimize the chance of experiencing an ozone/weather cracking condition over the winter months when the equipment is inactive.

Rubber compounds that are exposed to the atmosphere are formulated to resist deterioration caused by ozone. It may be hard to believe but the rubber compound properties constantly evolve due to their service and storage conditions. Improper storage can result in various tire conditions to develop including weather/ozone cracking also known as veneer cracking, dry rot, and weather checking if tires are not stored properly when not in use.

Ozone/weather cracking appears as a condition where small cracks/checks develop sometimes very quickly. This condition can appear from normal aging or late in its service life. It typically appears in higher stress areas on the tire near lettering of between the lugs.

Normally it does not affect the service life of the tire however, it can be aggravated by improper storage and/or exposure to high concentrations of ozone.

In order to help avoid potential tire degradation, maximize tire performance, and ultimately prevent premature removals, we generally recommend a few things to help minimize these types of conditions.  If you think about what causes the condition, the surface of the tire or rubber with tension or stress and exposed to sources of ozone and UV light the common sense approach would be to eliminate those.

In a perfect world the best case scenario would be to block equipment off the ground to remove the load and let air out of the tires to relieve the stress on the tire surface.  In addition, the unit should be stored in a covered environment away from sources of ozone which would include electric motors/machines, engine exhaust, welding equipment, battery chargers, transformers, and mercury vapor lamps. Other equipment that may produce sparks or electrical discharges should also be avoided. Covering the tires with an opaque wrap will eliminate the chances any UV light to attack the surface of the tires.  I realize that it seems like a lot of work, but if you follow any of these suggestions or you realize you are accidentally exposing you tires to harmful elements you can take whatever counter measures to minimize the risks.

Depending on who you talk to and the applications, tires can run for decades and be literally smooth and they still perform the job just as well as the day they installed them.  Of course those are rare but my point is that depending your performance expectation the idea of “worn out” may differ.  Most companies will consider a tire “worn out” when the tread depth is less than 80% or 90% of the original tread depths.  Warranties are based on this.  If you are experiencing excessive reduction in performance due to lack of traction then it may be time to start shopping for a new set of tires.

Typically tread depths on Ag tires are taken across the center of the tire between the nose of the lugs. Using a depth gauge is the best way but you can use a ruler or tape measure with a straight edge to get the same measurement.

Precision Inflation, LLC
Ken Brodbeck, VP of Technology

Time to change horses?

Some things never change.  Grandpa or Dad checked the team of horses every day.  Adding new shoes, repairing a harness or replacing a feed box.

Grandpa spent 5 to 10 minutes every day caring for his horses.  What if we spend 5 minutes per week checking our tires rather than brushing and feeding the horses?

At the end and beginning of the season:

  1. Check TIRE PRESSURE!! Inflate to recommended plus 2 to 3 psi for weather changes.  A tire monitoring or On the Go Inflation System makes this simple!
  2. Check for any cuts or breaks in the tire tread, shoulder, sidewall and bead area.
  3. Is there irregular tread wear? This may stem from over or under-inflation!
  4. Store tires in a dark and electric motor/welder free area. Sun and ozone kill tires.
  5. Keep petroleum-based liquids and grease away from tires.
  6. Reset tire pressure at the beginning of the season for the machine’s heaviest load, such as a large front fold planter.
  7. At a minimum, check tire pressure once per week during use.

When to put the tire/horse out to pasture?

  1. When the R-1 or R-1W tire will no longer do the job!
    1. Excessive slippage in heavy drawbar applications
    2. Will no longer hold air and cannot be repaired
    3. There are numerous cuts or cracks into the tire cord body
    4. Your favorite tire dealer has a special rebate deal. A half worn tire may value to trade in for a new set of shoes!
    5. If you need to measure tread depth, choose the worst wear location, lay a straight edge across two tread bars and measure to the base of the tire with a ruler.

Our grandfathers took 5 minutes every day to feed and water the work horses, we should take 5 minutes a week to check our iron horses’ rubber shoes!

Michelin Ag
David Graden: Operational Market Manager – Agriculture

Over the years, I have seen many methods producers have used to either prolong the life of their tires or prevent the effects of winter storage on the following season. These would include parking their machine (tires) on wood or concrete blocks, taking weight off of the tires by raising the machine off the ground, covering tires with a sheet or tarp, increasing the air pressure to maximum psi, etc. The reality is, there are only a couple of simple actions a machine owner should take to help maximize the life of their tires and ensure optimum performance the following season.

After harvest season has come to an end, your machinery has been washed and you are ready to button up things for winter, I recommend parking your machine in a cool dry place. Washing your machine thoroughly will show evidence of any fluid leaking throughout the storage period. Additionally, make sure your tires aren’t sitting in chemicals, hydraulic fluid, fuel or oil. Petroleum based fluids will eat rubber and cause your tires to crack at the contact area.

Next, raise the air pressure of your tires to the maximum air pressure recommended on the sidewall of the tire. As the ambient temperature falls, so does the psi in your tires in addition to the natural loss of air pressure over time. When you return to use your machine, and pull out of storage for the season, reset your air pressures to the recommended psi. Your tire manufacturer representative should be able to assist you with this. As I have stated before, all Michelin Ag reps have the capability of weighing machines and recommending exact air pressures to help your machine perform exceptionally well.

Determining when a Michelin Ag tire is worn out is a great discussion with any end user. If you were to ask a producer to tell you when their tractor tires are worn out, they would probably give you a confused look and a response of, “When the tread is gone!”

Michelin Ag tires are standard R-1W with very specific rubber compounds and lugs designed to wear slower and more consistent than R-1 competition, as shown below. By design, when a Michelin Ag tire is deemed by many to be worn out, there is still plenty of tread with sharp biting edges with a consistent void ratio.

Rubber has a shelf life much like the bread in your pantry. Now that aromatic oils are no longer used in tire rubber, it begins to dry out as that tire ages.

For example, let’s say a typical tractor tire will last about 12 years, although the sidewalls are beginning to show significant age and reaching the end of their life- in many applications our tire will continue to complete the job efficiently with minimal slip due to design.  Further, many folks would add a tube and use as much of the remaining tread as possible.

If you wanted to keep an eye on your tread and track my thoughts here, Michelin recommends taking tread measurements at the center of the tire, at the lug nose. If your tire pressures are set to recommended psi for the weight carried, your tires should wear nice and evenly across the face of each lug. If your tires are not wearing this way, you could have a mis-mounted tire or have a mechanical issue causing that tire to wear unevenly. Consult your manufacturer’s rep for recommendations or diagnostic.

Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

After a hard season and harvest complete, it is now time to take a well-deserved break until the next growing season. This time of the year allows us to perform maintenance operations neglected during the growing season due to lack of time and prepare the equipment for a hassle-free performance next season.

It is important during this time to check your tires, as they are a key component of your operation. There are several points to consider when checking tires during the off season:

1 – Check for external damage that could compromise the tire’s structural integrity or performance. For example; nails, deer antlers, deep cuts, missing parts, etc. If any external damage is found, consult with your tire expert if you think it will affect the performance of the tire
2 – Check for correct bead seating on the rim and potential tire to rim slippage. If any issues are observed here let your tire expert assess the situation and correct if necessary.
3 – Check the bead area for material between the bead and the rim. If anything is found, be sure to remove it. If it’s difficult to remove let your tire dealer do it for you.
4 – Check the tire for signs of any uneven or excessive wear pattern that can be related to incorrect tire inflation pressure, incorrect tire size selection (that differ from a correct lead value depending on the tractor inter-axle ratio), excessive tire to soil slippage or damage/wear on steering components.
5 – Check the height of the lugs and replace the tires if the lugs are below 20-30% of its original height. The original measurement can be found in the tire manufacture data-book and web page. The lug height, or tread depth, is defined as 32nd of an inch and must be no less than 20-30% of the original value. If it’s below this value, the recommendation is to replace the worn-out tire. Low lugs significantly reduce the capability of the tire to transmit the equipment’s power to the ground, increasing the tire to soil slippage. The height of the lug can be checked by placing a flat plate between two adjacent lugs and measuring the depth of the inter lug area. This measurement must be taken at 1/3 and 2/3 of the length of the lug. Check in several areas of the tire.
6 – It is always recommended to store the equipment inside a shed and away from direct sunlight. Direct and prolonged exposure to sunlight can create superficial cracking and potentially dry out the tire.
7 – If possible, lift the equipment and place it on stands to allow the weight of the load to be released from the tires. You can also increase the inflation pressure so the tire maintains its round shape as much as possible. Take in to consideration that no tire is 100% air tight, so the tires will lose some air over time. Once the new season starts, recheck and adjust the inflation pressure to the recommended values depending on the equipment and application.
8 – If the tires are removed from the equipment to be stored during the off season, for example a floater set for sprayers, be sure to store them standing upright.
9 – Clean the tires as much as possible to remove dirt and other debris.
10 – Don’t allow the tires to come in contact with petroleum-based products or solvents.
11 – It’s recommended, when replacing worn out tires, to choose the same brand and size already installed for each axle of the equipment. This is because they are approved by the OEM’s. Tire specifications vary slightly between brands, even for the same nominal size, and it can damage your transmission if not chosen correctly. Also never mix radial with bias tires or R-1 with R-1W.
12 – In case you decide to change the size of the tires, consult with your equipment dealer to ensure the change is acceptable. Having a “non-approved” tire combination can damage your gearbox and final drives.

Always remember that the tires are a fundamental part of the equipment and taking good care of them will assure the correct, expected performance.

Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

Before planting begins, farmers should perform a standard equipment check to make sure tractors, tillage and planters are in good working order. Checking oil, hoses and fittings is typically at the top of mind – but we can’t forget about tires. Firestone Ag has created a seven-step Tire Check list to help farmers quickly but effectively check their tires this off-season so they can maximize up-time when planting and growing seasons arrive.

The Firestone Ag Tire Check list provides seven steps that help to identify signs of tire wear. Regularly checking tires can help prevent and avoid more time-consuming problems in the field, therefore increasing the tires’ lifespan and a farmer’s profitability. After completing the 7-step list, if any abnormalities are found, a certified Firestone dealer can inspect the tire to know if repairing or replacing the tire is the best option for the farmer.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

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James Tuschner <![CDATA[R-1 or R-1W: TIRE MANUFACTURER’S ANSWER]]> https://agtiretalk.com/?p=1252 2018-12-29T16:56:23Z 2018-12-29T03:40:00Z  

 

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)
Scott Sloan: Ag Product Manager / Global LSW

In the ag industry traction tires are classified by the depth of tread using the nomenclature R-1, R-1W. This industry standard allows tire manufactures to work within the standardized classifications so machine manufacturers and end users can properly compare tires. The R-1 has been the standard general farming tire for decades. Tread depths for R-1 tires depending on the size will run from 1.25” to 1.75” deep depending on the size of the tire. R-1W is of European origin, some call it the European R-1. R-1W tires are generally 20%-25% deeper than a standard R-1

That being said the question then arises what are the benefits of both and what applications are best for each. Typically on smaller HP tractors (<150HP) the manufacturers will fit the tractors with the R-1. These tractors are used in lighter more general applications. In addition R-1 tires tend to be less expensive and more cost effective for the manufacturers. However, R-1 tires do tend to perform better in some applications. In applications where the tires will see dryer harder conditions the R-1 will outperform and outlast the R-1W in most cases. R-1W’s perform better in softer slightly wetter soil conditions and typically clean better in those wetter conditions.

For example, a self-propelled sprayer is a good candidate for R-1 tires. The 25% deeper lug of the R-1W tends to leave deeper lug or cleat marks in the field and when making turns on the end rows they tend to rut and disrupt the residue more. During long transport runs the deeper lugs tend to heat up and flex more causing premature wear. Another example would be in scraper applications where due to the deeper lug of the R-1W in the high torque hard surface application the taller lug tends to be more unstable and flex causing lugs to sometimes be torn from the tire.

Up until now there has not been an R-1 choice for operators on the larger volume tires for larger tractors in the more arid regions, scraper applications or larger floater options for sprayers. The entire market has been R-1W’s. Titan is introducing the Optitorque Radial R-1 line expansion coming out with the 710/70R42 and 800/70R38 sizes for those operators and applications that an R-1 will outperform the R-1W. At the end of the day it really is up to the end user to determine the conditions he is running in and determine what tire they should be using and what will work best for them. They also need to make sure when comparing tires and tire brands, some may be comparing an R-1 to an R-1W , the good news is now at least, they will have more choices.

Continental Agriculture North America
Harm-Hendrik Lange: Agriculture Tires Field Engineer

Originally, the standard pattern was the “R-1” type and the “R-1W” (“W” stands for “wet”) was seen as the specialist for wet soil types with approximately 20% more tread depth. Between 1950 and 1975, developments were made in the agricultural tire business, such as the standard fishbone pattern and the radial agriculture tire. During this time, the “W” type became more popular and the preferred type for many farmers around the world. Today in many regions, the R1-W is the “standard” pattern with some tire lines only available in the R-1W pattern.

A reason for the R-1W preference may be that farmers expect 20% deeper tread to provide a 20% longer lifetime. Additionally, due to the more aggressive pattern, they may expect higher traction on the field.

With improved tire technologies and changes in operation today, this logic is not quite valid. From a wear perspective, the individual tread design and compound properties are much more important than the difference between R-1 and R-1W. For example:

  • Comparing R-1 and R-1W, the deeper tread patterns often have smaller lugs, so the amount of rubber material withstanding wear is often the same on both tread types. In the end, this should result in comparable lifetime.
  • To have proper self-cleaning with heavy soil types in combination with deeper tread, the distance between lugs needs to be greater. This also reduces the amount of rubber withstanding wear on the R-1W types.

The amount of road transportation and transport speeds have increased during the past 20 years. On the road, the R-1 can have the advantage:

  • On average, they have a wider lug surface making contact with the road/hard ground which allows a better force transfer.
  • Lower lugs allow better intersection of the lug front on the road without trouble for self-cleaning on the field. This allows tire designers to optimize rolling comfort properties with less limitations, such as noise and vibration.

Of course, tractors are mainly designed to work on the field and less on the road. So, let´s look at the differences between R-1 and R-1W in field applications.

Soil types are quite individual. Even the same soil type can have different characteristics depending on the thickness of different soil layers, the distance to harder underground layers, and individual and changing weather conditions that impact humidity content. A general recommendation for R-1 or R-1W based only on soil type cannot be made.

As the “W” for “wet” says, 20% more tread depth shows significant traction advantages, especially on wet soil types where the lugs sink completely into soil. This additional traction is only given if the soil between the lugs is compressed properly though. If the soil is too dry, or the ground underneath the loose soil is too hard, the compression of the loose material won’t occur in the interlug section. In this situation, a lower tread depth will compress the soil a little bit more allowing additional traction force to be transferred, like the following picture displays.

Recommendations for Farmers

Lifting the implement, driving over an exemplary soil area and “reading” the imprints of the tire from time to time can tell farmers about the situation of the “gear-pairing” between their specific soil condition and tires. This builds up expertise for the next tire selection.

If the traction forces don’t deem an advantage of one type over the other, consider the increased risk for wrinkles in the connection between the lug and tread base associated with higher lugs.

Another factor that needs to be considered for the choice between R-1 and R-1W is the application. On many soil types, especially when wet, the “W” type can generate better traction. But for many applications, the traction is not the limiting factor, such as seeding applications or PTO-driven implements. Here a wider and more even footprint of the R-1 or even a partly worn tire causes less impact to the soil, which needs to be eliminated by the implement.

One quite special and sensitive application is the grassland operation where deep and sharp lugs can cut the turf surface. The effects from this may make the track areas unusable if mud or earth could be picked up in the silage and harm the fermentation. The right tread design and tread depth is very important here.

A good example to always use the optimum tread depth is practiced in the Netherlands. They have an active sale and resale market with realistic prices for used tires. In wet soil areas for tillage and ploughing, new R-1W tires with less than 50% wear can be used. Afterwards the partly worn-down tires are welcome to be sold in their wide areas of grassland farming with wet surface conditions that are highly sensitive. They are used in this grassland application until worn down completely.

Trelleborg Wheel Systems
Norberto Herbener: OE Applications Engineer

First what is a R-1, R-1W, R-2, HF-1, F-2 etc.? It defines the tread pattern of each tire and follows norms/rules established by TRA (USA) and ETRTO (Europe). R-1 and R-1W are the tread patterns used mainly for traction in agriculture and is the typical lug type design. The main difference – defined by norms – is that the lug of an R-1W tire is 20% taller than the lug of an R-1. R-1W is an evolution of the R-1 that started in Europe as the soil conditions there are normally more humid than in the U.S. From there the W in R-1W means WET.

Trelleborg Progressive Traction

Each tire manufacturer has it’s own lug design (width, length, angle, shape, quantity) and follows his experience and development to provide the best traction capabilities in each soil condition. Trelleborg with the exclusive Progressive Traction (PT) line up adds an additional small lug in the base of the normal lug providing an additional anchor point. The result is an improvement in traction increasing the power transfer from the transmission to the soil. This wider lug base also increases the damage resistance of the lug.

Most Europe based tire manufacturers – as Trelleborg – offer a complete Radial R-1W (WET) lineup, combined with the flexible sidewall tire construction, that deliver a flatter tread profile than conventional R-1 tread pattern. This design provides a larger footprint on the ground, with more and longer lugs contacting the soil at the same time and deeper into the soil. This provides a higher traction (less slippage, less fuel consumption) and lower compaction on the soil compared to R-1.

Having a tire that can perform under wetter condition without compromising performance expands the working window available for each job.  Also, another advantage of R-1W is as the lugs are 20% taller and a flatter profile, the tire has a longer and more even lug wear life as conventional R-1.

There are some cases where a R-1 lug height design performs better than a R-1W. This is the case with sprayers and spreaders. This equipment is traveling at high speed with full load on the road (hard surface) where all the pressure is on the lugs only. This high lug movement on hard soil generates higher amount of heat (worst enemy for tires) accelerating the wear of the lugs. In this specific case the tire manufacturer created sprayer specific series (Trelleborg with TM150) with a R-1 lug design height, but increased the number of lugs. This concept allows the load to be distributed on more lugs and generates less heat with faster dissipation.

Finally, it has been a custom to use the R-2 design (taller lugs) in muddy conditions like in rice fields. The traction performance and grip are superior in these muddy field but was not adequate at all for not so muddy soil condition or road transport. The lugs would suffer high stress, bend with higher damage possibility, higher wear and very uncomfortable ride. Trelleborg in order to offer an alternative to these conditions has developed and launch recently to the US market the 480/80R50 TM600 Rice PT with a new and innovative R-1W+ profile. These lugs of these tires are taller than the “normal” R-1W but shorter than a R-2, combining the positive aspects of both tread pattern (R-1W and R-2) and the exclusive Progressive Traction concept from Trelleborg.

In sum, always think about the specific application when choosing whether to use R-1 or R-1W.

CEAT Specialty Tires Inc.
Jim Enyart: Technical Manager

Why would a dealer recommend an R-1W over an R-1? Why would a farmer buy either one?

The difference between the R-1 and R-1W is the tread depth. The “W” designation stands for “Wet” and has approximately 25% deeper tread depth. Remember this is an approximate! The reality is that when comparing tread depths between different product lines from the same manufacturer or from different manufacturers, there are most likely other design differences than just the depth of the tread. These differences should be a primary concern in the buying or selling process. Tread depth should be a secondary concern.

The primary objective should be to identify the best product for the application, period! Making the best choice can only be achieved by identifying the application as well as the features and benefits that are needed or required. Does the specific application require increased load carrying capacities, high speed capabilities, maximized traction, flotation . . . or does it just need to hold air for the application? The application and features required should drive you to the best product. The answers may lead you to bias, radial, high speed, flotation, row crop, IF, VF or even IF CFO product lines, among others.

In the majority of cases, multiple tread depths are unlikely to be a factor in making the purchasing decision.

Comparing the various options based on a cost per 32nd of tread depth helps with cost comparisons. The R-1’s will cost less due to reduced tread depths which translates to less rubber in the tire. Don’t get caught pricing a “tire” against another “tire” without the details or you may get caught appearing to be out of the market price-wise!

Tread depths can enter in the buying decision where the equipment is only operating in dry conditions or is not utilized in applications requiring maximum power to the ground, or other high-performance features.

No farmer plans to operate their equipment in wet, muddy conditions but when they have to, they would be better served with R-1W’s over R-1’s due to the additional traction the deeper lugs can provide. Dry conditions either stay dry or go to wet and wet conditions only stay the same or go towards the dry side with time. Amazing! It’s much better to be prepared with the deeper tread depth radial tires for wet conditions because down time during harvest season can really hurt the bottom line.

If you are comparing costs of an R-1 vs an R-1W you should see at least a 25% price gap to seriously consider the R1. The R-1W has about 25% more tread depth and in the majority of applications, the increased tread depths will deliver a longer service life that will correspond with the increased tread depth percentage. Keep in mind when you start with an R-1W you can run the tires for quite some time and with the right amount of tread removal, you will then have your R-1.

If pricing is the only consideration, then the cheaper the better. But the cheapest tire may end up being the most expensive in the long run. We tend to get what we pay for.

What is the best buy? It is very simple . . . the correct tire for the application and operation. The tire that provides the performance and trouble-free service life that fits the farmer’s needs is by far the best option.

Just keep in mind . . . a deeper treaded R-1W might provide a bit of insurance against wet conditions when it is needed the most!

BKT USA, Inc.
Dave Paulk: Manager Field Technical Services

Before the R-1W was introduced to the U.S., there was an R-1 and R-2. The R-1 was designed for general farming, while the R-2 was designed for extremely wet conditions such as with rice and sugar cane (Rice and Cane tire). These tires were used before radials were popular and bias tires were most common.

As equipment got larger and heavier and farming practices changed, bias tires gave way to radial farm tires in most types of farming. Radial tires are designed to carry heavier loads at less air pressure and generally last longer when they are driven on the highway. Because of the body construction, bias tires have a tendency to squirm and wear out quicker when run on the road.

The R-1W was originally designed as a fit between the R-1 and the R-2. The R-1W has approximately 20% deeper tread than an R-1 and 20% less tread than the R-2. With today’s tire and compounding technology for radials, the R-1W is used where both the R-1 and R-2 were used with bias tires.

The R-1 is designed for general farming in dry dirt as the tread depth is not as deep. The R-1W is also used in this application and has a 20% deeper tread, providing a longer tire life. This is important because farms are now scattered and tractors must be transported on highways to move between farms.

R-2’s were designed for muddy conditions and is still the tire of choice for crop such as rice, cane, and vegetables in irrigated soil. In some of these conditions, the R-1W is used where the dirt is wet, but not muddy. The R-2 does not do well when they are driven on the road because the lugs are deep, bend easily, and can develop uneven tread wear.

The R-1W is a good all-around tire to use for general farming practices. BKT makes this tire with a 45-degree angle that does well in the field and rides and wears well on the highway. The extra tread depth gives it longer wear and more value for the money paid.

Radials in general are better than bias tires where soil compaction is a concern because they can be run at lower air pressures with higher load carrying capacities to lessen soil compaction. BKT radials are designed with a flatter footprint to distribute weight evenly. BKT also makes tires in the IF and VF design to lessen soil compaction where needed. The IF carries 20% more weight at the same air pressure as a standard tire and the VF carries 40% more weight at the same air pressure as a standard tire. Less air pressure equals less soil compaction, producing better crops.

Alliance Tire Americas
James Crouch: National Product Manager—Agriculture

R-1W tires have taken the farm tire market by storm, and it’s no mystery why. Just a few years ago, these extra-deep-lug farm tires were super-premium offerings, reserved for the biggest tractors and the largest farmers. Now, most of the top tire manufacturers have R-1W tires, prices have come down, and the deep-lug technology is within reach of most farmers.

When it comes to extra traction, heavy loads, and lots of torque, R-1W tires are the way to go.

Think of an R-1W as a classic R-1 directional tractor lug tire plus 20 percent more depth. The “W” in “R-1W” actually stands for “wet,” to indicate its increase in wet traction versus a traditional R-1. That’s perfect for Midwestern or Southern soils—gumbo soils or sandy loam where you want more bite. That R-1W lug is going to grab more earth and propel the tractor forward more effectively, while the area between the lugs keeps the tire on the surface of the soil.

And nowadays, with fields spread farther apart, it’s nice to have some more rubber to extend tire life on equipment that spends more time on the road. Beyond the extra depth, today’s R-1W tires also have better compounding than ever, which is great for longevity.

That said, sometimes all a farmer needs is a good, classic R-1. Say you’ve got a small chore tractor in your equipment yard—70 horsepower, loader on the front or a box scraper on the back—that doesn’t even leave the farm. You don’t need an extra-deep lug tearing up the ground for that. And if you’ve got a tractor that’s just pulling a tedder and a baler around a hay field, you don’t need the added expense of an R-1W. Basically, you’re not going to wear out that R-1 tire on a haying operation, so why pay more for extra tread you’re not going to use?

Another situation where it may be better to stick with R-1 tread rather than going to R-1W is on a high-clearance sprayer. The deeper R-1W lugs on a 380/90R46 tire will squirm more than the shallower ones on an R-1 of the same size. Obviously, that’s a disadvantage when you’re trying to run straight between the rows or steer a few thousand pounds of spray solution down the road. The R-1 will give you a more stable ride and build up less heat on the road between fields. Definitely a better choice for that application.

On the other hand, sometimes you want even more lug than an R-1W can deliver. In the muddy fields of rice and sugar cane in the South or sugar beets in the North, some farmers invest in R-2 tires, which have massive lugs more than 3 inches deep.

An R-2 tire works differently than R-1 and R-1W tires do. Instead of floating the tractor or combine up on the surface of the soil and reaching in for traction, R-2 lugs actually dig deep and scrape a layer of mud off the surface, clawing for drier soil below where they can get traction. The angle and lug design are extremely aggressive—more aggressive than you’d want in a drier field, especially if you are trying to stick to minimum tillage or no-till.

Working with a tire dealer in Arkansas, Alliance just designed a revolutionary R-2 tire. Our new Agristar 374 R-2 tire delivers great traction, excellent self-cleaning—which is vital to keep tires from turning into clay-coated racing slicks after their first rotation in heavy, wet soils—and outstanding performance on the road. The old R-2 standards that have been on the market since the ’60s are poor performers on the road: the deep lugs gave a bouncy ride, and because they were so tall, they tended to squirm a lot. That also built up a lot of heat, which, as we know, is a sure way to kill a tire.

We completely redesigned the lug on our new R-2 tire. It’s deep—105/32″—but we’ve built it with a stair-step-style construction, tapered out at the bottom and anchored to a lug bar in the center of the tire to minimize squirm. Those truncated stair-step shapes also provide more biting edges in the mud for extra traction, and a wide nose on each lug smooths out the ride and improves steering even further. And everything about the sidewalls enhances the tire’s performance, from enhanced heat dissipation to extra flex that maintains a flatter, more even footprint for better traction and longer road wear.

So if you look at the variety of lug tractor/combine tires on the market—from standard R-1s to the extra 20 percent depth of an R-1W to the massive R-2 that is a full 3 inches deep—you can really take your pick of the tire that’s going to deliver the performance you’re looking for…and paying for.

Precision Inflation, LLC
Ken Brodbeck, Vice President of Technology

When should a user select a R-1 or R-1W? See the comparisons below:

R-1W over R-1:

  1. 20% more life, especially if the machine does a significant amount of road travel.
  2. Better tractor resale value.
  3. Minor loss in traction over R-1 on firm dry soils.
  4. Minor traction advantage in wet muddy conditions.
  5. Eventually R-1W will become an R-1 tread after roughly 1000 hours.
  6. Rear Sizes over 80” in diameter are only offered in R-1W.
  7. Soil Compaction is directly related to tire pressure. R-1 and R-1W use the same load/pressure table. To minimize compaction, know your axle load and set the tires to the minimum pressure required by the tire manufacturer and check weekly. If you do not check tire pressures regularly, you should run 2 to 3 psi higher than the minimum to protect your tire investment.

R-1 over R-1W:

  1. R-1 bias and radial are usually the lowest cost tires for low hour use tractors.
  2. R1 treads are the favorite for most tractor pullers due to better grip on hard pulling tracks.
  3. Think of a high horse power tractor puller using a slick with ¼” high tread bars. They win on firm tracks!
  4. Older lower horsepower sizes may only come in R-1 tread.
  5. Soil compaction, see point #7 above.

What about R-2 – Rice and Cane Tread?

  1. R-2 tires work well in true mud with a solid plow pan.
  2. In mud without a plow pan, you quickly bury the machine.
  3. R-2 tires are expensive, rough riding on pavement and do not pull as well in normal moisture soils.
  4. How about for “insurance in wet harvests?” You will probably be better off buying a large flotation size to keep tire pressure low and float over the soft spots.

Michelin Ag
David Graden: Operational Market Manager – Agriculture

R-1 and R-1W are tread designations used to describe a tire tread bar typically a corresponding usage. Most common designations found are R-1, R-1W, R-2, etc.

R-1 is a standard tread and typically used in applications that demand very little from the tire. For example, you may find an R-1 lug tire in dry farming or on general purpose chore tractors. And in some applications, conditions need to be ideal.

R-1W is typically considered a wet traction tire for use in softer soils. This lug design can have larger voids between lugs and deeper lugs than an R-1. These tires are also considered a deep tread or premium option for most tire manufacturers.

Here at Michelin AG, we only make R-1W tires. When it comes to putting more horsepower to the ground and improving traction in your less than ideal everyday conditions, let’s be honest. Think spring planting. No one has the luxury of working in ideal conditions. The standard R-1 just isn’t enough.

Take a look at the lugs on your AG tires next time you get the chance. What you will notice is an almost A-framed design, sweeping up at an angle from the front and the same angle back down along the trailing side. The basic reason for this type of lug design is stability. Unfortunately, as this type of lug wears, the biting edges will round over and eventually create a lug that resembles an angled bump instead of a tread bar.

The standard Michelin R-1W, however, will maintain those biting edges and deliver exceptional traction when up to 70% worn with up to an additional 50% tread life. The Michelin lug design is really to blame for this exceptional performance. Not only do Michelin rubber compounds tend to wear slower, but more rubber tends to bring longer tire life. Additionally, the upright nature of Michelin lugs leaves a very consistent shape throughout the entire life of the tire. This translates to traction, which in turn, burns less fuel by operating more efficiently.

Finally, since R-1W is the designation for all Michelin AG tires, our standard tire pricing isn’t far off from our competitor’s standard tire pricing. Meaning, you could purchase a Michelin Agribib 2 for a very comparable price as our leading competitor’s standard tire. The difference is you are getting much more tire at an even better price with Michelin. After a few years, you’ll have an R-1.

Firestone Ag
Bradley J. Harris: Manager, Global Agricultural Field Engineering

When choosing to place radial traction tires on a tractor, one of the most common questions we hear is whether R-1 or R-1W tires are best. When looking at the price difference between the two tire types, farmers wonder what they get for the higher price of an R-1W. To help farmers make the most informed decision, here are some facts and performance benefits for R-1 and R-1W tires.

The language itself, R-1 and R-1W, is a tire industry standard defining the minimum designed tread depth of an agricultural traction tire. The Tire and Rim Association defines the minimum bar height based on the tire width and the aspect ratio (height of the sidewall). The R-1 designation is the standard tread depth. The tread depth of an R-1W tire is at least 20 percent deeper than the same sized R-1 tire. In simple terms, R-1W tires have a taller bar height, but all the other dimensions, such as overall diameter and rated load capacity, are the same between the R-1 and R-1W tires.

There is not a substantial performance difference between the two types of tires – particularly for farmers who are concerned about soil compaction. Soil compaction is the result of the axle load and the inflation pressure to carry the axle load. Since the two tires have the same load and inflation pressure, the tires will create the same amount of soil compaction. If farmers are concerned about soil compaction, it is more important to look at tire sizes or IF and VF tires that carry the axle loads of their tractors at pressures below 15 psi.

  1. The traction difference between the two tires depends on the soil conditions in which the tires operate. The deeper R-1W tread depth does not automatically mean the tire has more traction. Traction is dependent on tread bar shape and the angle of the bars. However, when deciding between the types of tires, pay close attention to soil conditions and consider the following:
    Dry or normal soil moistures can use an R-1 tire. The R-1 and R-1W tires will have similar amounts of traction. Both tires work great in these soils, but if a farmer is debating the two tires because of cost vs. performance, the R-1 tire is more cost efficient.
  2. In wetter soil conditions, even if they are borderline, consider using an R-1W tire. Just like in dry soils, the R-1W tire doesn’t generate more traction over the R-1, but the deeper skid will help maintain traction in higher slip ranges. The extra cost of the R-1W helps ensure traction in those areas, which helps with time and fuel efficiency.
  3. In wet soils, like those in the Texas Bayou or the Gulf Coast region, neither the R-1W or the R-1 are the best choice. Instead, farmers could look to move up to an even deeper tread on R-2 tires. The tread depth of an R-2 tire is two times deeper than R-1 tires to help gain traction in those wet soils.

After considering the soil conditions, think through how often the tractor will be running on paved surfaces like the roads or concrete feedlots. If a farmer doesn’t have to drive many miles on the road to get to their fields or doesn’t operate in a concrete feed lot, then an R-1 tire is a good, cost effective solution. If a farmer does travel long distances to get to their fields, or if the tractor operates in concrete feedlots, move to an R-1W tire. The deep skid will allow the farmer to put more hours on the tractor before the tires need replaced.

Above all, consult with your local tire dealer to determine what type of tire works best in your area. It’s not always necessary to move to a more expensive type of tire based on traction or performance claims. If the conditions allow it, sticking with an R-1 tire may be a way to reduce costs in equipment maintenance.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

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James Tuschner <![CDATA[Can BIAS Tires Beat Radials?]]> https://agtiretalk.com/?p=1222 2018-12-10T20:30:52Z 2018-12-01T21:11:43Z  

 

Can old school 1930’s Bias Ply Technology provide better traction than latest High Tech Radial?

The short answer is YES!

I don’t believe it, you say.  Surely these high tech radials must always out-pull Dad’s Old Bias tires, right?

The answer depends on your tire pressure!

When your New Radial’s air pressure is matched to the axle load, they will always out-pull their Bias counterpart. But if the Radial is over inflated, the Bias tire with the correct air pressure will probably win.

The sad truth is many farmers over inflate their tires for various reasons:

  • Tire Looks Low.
  • The Tire Changer Erred on the Safe Side:  tires were set at 25 psi and may only need 12 psi.
  • Tires were Inflated for a Heavy 3 or 2 Point Implement or Planter, then not deflated for a disk or pull type ripper.

OK, sounds reasonable, but has anyone ever tested Bias vs. Radial head to head?

Yes!  In my career at a major agricultural tire manufacturer, we tested a new Bias vs new Radial with the exact same tread pattern to confirm.

The tractor was a 4WD hooked to a load unit that measured pull and slip in real field conditions.

Results:

Correct inflation was 12 psi for both tires.

The results were what you would expect.  With both tires at 12 psi, the Radial out-pulled the Bias by 7 to 9%.

We then over-inflated the radials to a typical field pressure of 20 psi.

The 12 psi BIAS tire BEAT the 20 psi RADIAL!

What does this test mean for you and your tractor?

If you are running over-inflated radials, you are probably:

  1. Burning More FUEL
  2. Seeing More TIRE SLIP
  3. Creating More SOIL COMPACTION that can reduce yields.
  4. Creating Deeper RUTS in soft fields.

My advice, contact your local tire dealer to properly set your tire pressures, unleashing all of the benefits your new new age high tech radial AG Tires can provide.

When you do, your wheel tractor will probably give the track tractor a run for its money!

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

Ken Brodbeck is an Ag Engineer who spent 35 years at a major ag tire manufacturer. He is now Co-Owner of Precision Inflation, LLC, an Independent Dealer for German PTG Inflation Systems for Agricultural Machinery.  precisioninflation.com

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James Tuschner <![CDATA[Reduce Stubble Damage: TIRE MANUFACTURER’S ANSWER]]> https://agtiretalk.com/?p=1152 2018-11-03T22:58:33Z 2018-11-03T15:49:02Z Continental Agriculture North America

Ralf Krieger:  Head of Development and Industrialization of Agricultural Tires

There are several trends in modern agriculture that increase the risk of stubble damage. Due to the quick development pace of operating procedures, tools and tires are attempting to keep up:

  1. The modern plant breeding process is much faster with genetic engineering. The goal to have a more stable plant that is resistant against windstorms and pests leads to a very firm plant structure.
  2. To extend the yield of the feed harvest or biogas production, the plant cutting height is reduced year by year. The remaining stubble is shorter and not easy to tumble over.
  3. The fight against pests, like the corn moth, also demands a low cutting height.

The potential on the tire side is limited by the need to balance flexibility and protection. A good strategy is to bend the stubble before it can penetrate the tire.

Structurally, a low tread pattern and a hard, durable tread compound would support this. A tire used for loaders in a quarry would be better against stubble; however, it would cause heavy compaction of the soil, lower traction forces and less vehicle mobility due to the high stiffness. As a result, these tires aren’t efficient for agriculture and most of the tires used on the front axle of modern tractors need to have a traction pattern. Here the situation is slightly different.

Depending on the size, structure and geometry of the tread pattern, the stubble is clamped and guided to the tire surface. The result is high contact pressure with the possibility of damage. If the tire survives the first 1,000 hits, more will come and cause cavitation at the rubber surface.

To minimize the risk, the pattern shape can be optimized. A 45° orientation of the lugs is better than 23°. A flat slope in front of the lug is better than a steep one. In this special case, a soft rubber can help give a larger contact area between tire and stubble to prevent penetration. The Continental Tractor70 and Tractor85 are designed with a flat front slope and a 45° lug orientation to meet these challenges.

To avoid penetration of the stubble through the carcass, which can cause air loss, stronger carcass and belt reinforcements can be used. Steel cord is the best material and has been used in forestry tires for over 40 years. However, it can negatively influence agricultural performance with higher stiffness, less efficiency and higher material costs. The Tractor70 and Tractor85 do not have a steel belt. Instead, they are built with N.flex technology, a patent-pending material that has high impact resistance due to the high elongation of nylon. The material also has high robustness, enabling the carcass structure to absorb impact energy without breaking.

In addition to tire selection, growers can use a mechanical stubble breaking device which quickly covers the cost of itself. Corn headers with steel sliders and steel rollers in front of tires to bend the stalks are very efficient tools. If a tractor is equipped with a front hydraulic system, the stubble breaking can be managed together with the cultivation in one operational step.

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)

Scott Sloan:  Ag Product Manager / Global LSW

Stubble is an ongoing challenge for end users and tire manufacturers.  All tire manufacturers deal with it, if they say they are not they are lying, it is just a fact and end users constantly battle it.  Stubble has become more of an issue over the past couple of decades for many reasons. Seed populations have increased from an average of 24K per acre to almost 55K.  Genetics have also improved to enhance plant health against insects and climate conditions. So now is there not only more of them, they are much more robust- so tires are exposed to twice as many plants that are much more likely to damage a tire.  On any given year weather conditions like drought, and freezing play a huge part in the aggravation of stubble damage.  Chopping heads have not helped the situation either, as stalks cut 3” to 5” do not allow the tires to push the stalk over to minimize penetration into the tire, essentially creating a field of rebar that the tires have to cross.

Tire companies can only do so much with the compound.  Everyone says we need to make the compound harder.  We work within the “Magic Triangle” when it comes to compounding.  The area of the triangle is constant, if the compound is changed to affect a certain physical property, another property of that compound will be affected also.  In the example below, when the compound is made “harder” the stubble resistance goes up, but in so doing the compound lost its crack resistance property.  The tire may not show signs of stubble but the end user will be just as unhappy when the base of the lugs or sidewalls begin to crack out.  It’s a delicate balance. Its not that we aren’t working on it, we are constantly evaluating new compounds to find that balance of stubble resistance and tire longevity and performance.

STANDARD

STUBBLE

We have also developed special lines of tires specifically designed to fight stubble penetration.  Implement tires come to mind that are used on seeding and tillage equipment, these tires are especially susceptible to stubble.  We have developed a line that incorporates our stubble resistant tread compound and a construction that uses significantly more actual body plies along with Kevlar Belts.  Our Stubble Guard Implement line has proven that stubble penetration can be combated successfully.  The picture below shows the STANDARD tire (top) found on a piece of seeding or tillage equipment and the STUBBLE GUARD tire (bottom), detailing the difference in construction.  The original set of Stubble Guard tires that were placed in 2011 are still running today with no flats after the original set of factory tires had six flats the first season.

STANDARD vs Kevlar Belt STUBBLE GUARD

So what can grower do?  I get asked that all the time.  First of all, you need to be proactive.  If you think about it, front tires on a tractor are replaced 3 or 4 to one with the rears for stubble.  One could ask themselves why.  The answer is that the front tires are taking the hit and knocking down the stalks ahead of the rears.   I always suggest taking a common sense approach,  Insanity: Doing the same thing over and over again and expecting different results”  – Albert Einstein.  Growers spend thousands of dollars replacing tires chewing the ear of their tire salesman off while they are handing him that big check because of the cost, then takes that tractor right back into the same fields not doing anything different “hoping” for different results.  That is insanity.

My suggestion to all growers that own any brand of tire is to get something in front of the tractor or combine to knock down the stalks ahead of the tires.  Just by doing that they would double or triple the life of the tires.  I am a huge advocate of mechanical devices that are attached to the equipment like stompers , rollers or any one of a multitude of products that are out there.  A minimal investment now will pay dividends for years.

Alliance Tire Americas

James Crouch:  National Product Manager—Agriculture

Stubble damage is a significant challenge for farm tires. It’s gotten worse over the years as seed companies have bred for standability, which has resulted in stiffer, stronger stalks and stubble that can do significant damage to tread rubber and sidewalls.

No tire can eliminate stubble damage, but there are a couple of approaches that can help reduce it.

The first step doesn’t come from a tire company at all. Invest in “stalk stompers” or some type of stalk roller, which are bolt-ons that knock over stubble ahead of your combine tires or tractor tires. The cost of a set of those shoes or sleds to mash down residue is less than the cost of replacing a set of premium farm tires, and it’s worth an hour or two of installation time to prevent having to stop to wait on the local service truck to arrive and fix the flat to get you moving again.

When it comes to buying tires, spend the extra money to buy tires with stubble-resistant compounds. Yes, there is a difference. When a manufacturer designs a tire, an important part of the equation is balancing the many ingredients in the rubber compound. Over the past decade or so, the industry has fine-tuned the use of natural and synthetic rubber, elastomers, coupling agents and other ingredients to create compound blends that are more puncture resistant than ever before. The chemical composition of the sidewall rubber and tread rubber are different, and both are uniquely blended to ensure both flexibility and durability.  It adds some cost, but saves dramatically on repairs and downtime.

Look for steel belts. That steel provides puncture resistance and has the added benefit of dissipating heat when you’re running at high speed, extending tire life. Aramid, also called Kevlar, also provides excellent puncture resistance.

The last shopping tip is to check with your tire dealer about your tires’ stubble damage warranty. Not all warranties are created equal—not only in terms of how many years they cover or the percentage they pay out based on wear, but also in terms of how quickly and easily the company adjusts a claim. If you’re planting or harvesting, you’ve got other things to do than fight with a tire company. That’s why we developed the ATG Warranty Wizard app and streamlined our warranty program—to get you back out into the field.

Once you’ve selected your tires, avoid the old habit of mounting your rear combine tires backwards. People used to do that for a smoother ride, but it accelerates stubble damage. Here’s why: the curved lugs of a combine or tractor tire, oriented correctly, are designed to guide stubble from the centerline of the tire to the outside, minimizing damage. If you turn that lug around, you’re actually capturing stubble from the entire footprint of your tire and channeling it to the center. That will cause a tremendous amount of damage to the lugs, especially at the center, and increase the risk that you’re going to get a puncture.

For more tips on how to protect tires against stubble, check out the Alliance Tire Americas video:  2-minute video rundown on stubble damage 

Maxam Tire International

Mark Turner:  Senior Product Marketing Manager, Agricultural Tires

Stubble damage has become an increasing topic of discussion between farmers over the last decade as new varieties and even hybrid crops have come into the farming arena. These new crops are more resistant to diseases, wind damage and other factors that can affect yield.

One of the ways in which these crops have noticeably changed is the strength of the stalk and this, combined with changing harvesting techniques, that leave a much shorter stalk in the ground, have contributed to the increase in stubble damage to tires. This seems particularly prevalent with certain varieties of Corn and Soy Bean crops.

In the past a longer stalk was easily pushed over by a tire rolling over it, so damage was limited however, today’s shorter and stronger stalks stay upright and can, in some cases, even penetrate the tire causing air loss and costly downtime.

Stubble damage mainly occurs in 2 ways, either cuts and penetrations to the tread or the sidewall or through chipping where repeated contact with the stubble causes small chips of rubber to be dislodged from the tread area, this can eventually lead to exposure of the cords and subsequently the need to replace the tire.

So, what steps can be taken to reduce this type of damage?

As with all applications, tire selection is very important, this type of damage occurs when tires are run over rows rather than in between rows, selecting a narrow tire that fits between rows can certainly help here. You can regularly see on wider tires which part of the tire was run over the rows as there is damage to only a small portion of the tread, but even this can sometimes be enough to require the tire to be replaced. There is also an opinion that using Radial tires rather than Bias type tires can help as they are more flexible and can envelope obstacles better.

Fitting front end attachments known as Stalk or Stubble stompers that push over the stalks before they contact the tire can substantially reduce the problem as these change the angle at which the stalk and tire meet each other and severely limit the chance for a penetration to occur.

As a tire manufacturer we constantly evaluate new materials and compounds that can help reduce this type of problem. Our extensive experience in earthmover tires that require rubber compounds that are very resistant to chipping and cutting will help us as we further develop our Agricultural tire range as we can evaluate which of these compounds can be used to enhance the performance of our tires in this area without affecting other important performance parameters.

Additionally, we investigate different reinforcement materials to use as breaker belts under the tread to increase protection against penetrations.

Finally, discussions with other farmers either through on-line forums or at events and exhibitions to find out what works for particular crop varieties or soil types is also a valuable way of sharing experience and information thereby saving costs and downtime.

BKT USA, Inc.

Dave Paulk:  Manager Field Technical Services

Over the past two decades, genetically modified crops (corn, soybeans, cotton, sunflowers, etc.) have been developed to produce higher yields and resist insects. While these new advancements can be beneficial, they don’t come without drawbacks. The stalks on these crops tend to be much harder, and if cut short during harvest, can damage tires. They become like pieces of steel sticking up in a field. As rubber tires run over these stalks, they can take chunks out of them. In addition, the stalks can puncture the tires and make them unrepairable and unserviceable. Sidewall punctures can be especially common when using radials and tires wider than the rows (as in no till and limited till).

As we all know, the main components of tires are rubber and fabric. Like other types of rubber, tires can only take a limited amount of abuse before failing. As rubber ages, it hardens and makes the tire more resistant to stubble damage.

You may be wondering “Why don’t manufacturers make these tires with harder compounds to resist stubble?” In reality, there is a narrow line to walk when compounding rubber for agricultural tires. What works well and improves the tire in one area can cause problems and failures in another. The longevity of the tire and traction must also be taken into consideration.

Stubble resistant compounds are used in some agricultural tires; however, they are mostly in implements. Implements have a lighter casing, causing them to be more susceptible to puncturing.  BKT Tires manufacturers the AW 711 and the Rib 713 with steel belts and stubble resistant compounding.

If possible, farmers should cut stalks a little higher than they would usually. This would allow the tires to push the stalks over instead of running directly over them. There are a number of attachments that can be purchased to fit on combine heads or mount on the front of tractors to do this job. Some examples are the Stalk Crusher (for combines) and Stubble Stomper (for tractors). While these attachments require an initial investment, they will save money in the long run.

Trelleborg Wheel Systems

Norberto Herbener:  OE Applications Engineer

Stubble damage will always be present (in a larger or smaller scale) and is mostly influenced by way farmers work in the field. Depending on the crop, usually the damage is more cosmetic and doesn’t influence tire performance – wheat stubble damage, for example. On the other hand, corn, soybean or cotton stubble can create significant tire damage.

Several points (independent of the crop or soil type and condition) should be considered when choosing wheel-tire size, design or special features.

The first point is tire quality and design. Choose a brand that has:

  • a low warranty rate (talk to your local tire dealer and neighborhood farmers for references)
  • the longest warranty (in years) including several years of stubble damage coverage
  • availability and service options at the local tire dealer carries –most brands offer a dealer locator on their webpage as reference.

Related to tire design, tire load capacity is mandated by the amount of air each tire can accommodate inside. The more air volume – the higher the load capacity. The second point is choosing tires with the largest balloon ratio possible (the second number  – 480/80R50 has an 80% ratio, for example) as the tire balloon will be taller and carry more air. Also, a taller sidewall – specially on tires with flexible sidewalls – allows for a larger sidewall bulge, which increases the footprint and reduces compaction. This larger footprint means the tire is more flexible and can adapt better to the soil or stubble beneath.

Another advantage of sidewall bulge on flexible tires is protecting the contact area between the rim and tire bead area, reducing the possibility of stubble entering the area and creating potential air leaks and tire-rim slippage. Always remember to set the correct air pressure for the tire size depending the load it will carry and the speed used to carry that load. First calculate the tractor weight needed (depending the tractor horsepower) and the optimal front-rear weight distribution (adding or removing ballast if needed), then adjust the inflation pressure following the manufacturer recommendation for each tire size.

Finally – check the design and quality of the rim. If the rim quality is poor or its damaged, it is possible that the tire will have issues and not be able to perform as it was designed for.

Next, let’s focus on the previously planted crops and how they will influence the actions the farmer can take to minimize the stubble damage. We will divide them into small grain and row crops.

Small grains – Are planted with small row spacing or without rows so there is no option to use tires that would fit in between rows –some part of the tire will always pass over the stems. The good news is that the stems are thinner, flexible and bend forward when the tire passes on them. Most of the damage is cosmetic and affect tire performance or durability. The alternatives to reduce this damage are choosing a tire offering a larger foot print, using a wider or a larger diameter tire (longer footprint) or a combination of both. Having a larger footprint will reduce the pressure on the stubble and the ground and the effect on the tire.

Row crops – These crops are planted at wider row spacing (the most common is 30”), with thicker, harder, and more aggressive stalks. The main recommendations are to work following the rows if possible (so that the lugs are not in contact with the stems), choosing the thinnest tire possible (580 vs 620 or 520 vs 580) to reduce the sidewall damage, and (especially in combines) using stalk stompers attached to the header in front of the tires.

There is basically no difference in rubber compound between sizes or models. Each tire has several “compounds types” depending on the function of that specific area of the tire and construction. Tread compound is different as the sidewall compound or the inner-liner compound and each one is developed to supply the best performance. The mix of materials of each of these compounds determines the hardness and flexibility of that area. The lugs compound will be harder and less flexible as compared to the sidewall compound for example. Years of experience and testing are involved in each compound recipe.

Lastly note the example of tractors used for roadside mowing or snow removal. In this case the most important factors to consider are the lug design with sharp edges and steel belt construction.

Michelin Ag

David Graden: Operational Market Manager – Agriculture

Throughout my time in Ag sales with Michelin, I have seen a lot of stubble and the corresponding damage it can cause to tires. However, there have been relatively few times I have met with a producer where stubble damage was top of mind. When I ask about the stubble I see on their tires, the response I typically get is something along the line of, “It’s just the cost of doing business.”

Unfortunately, as crops grow taller, stronger, and produce more yield, stubble damage will become a greater concern for the farmer.

Today, there are many different methods for combating stubble. There are rollers, stubble stompers, homemade devices, burning, and more. While many of these will achieve the objective, the unfortunate side effect is that these solutions come at an additional cost and a little frustration.  Furthermore, these methodologies can be time consuming and require periodic maintenance, and in the worst case, your tires may still see damage caused by stubble.

It doesn’t have to be a cost of doing business, though.

Many years ago, Michelin R&D teams invested a significant amount of time and resources designing tires for superior stubble resistance. The result is Michelin Stubble Shield rubber technology. Stubble Shield is a specialized rubber compound and anti-stubble reinforcement in the tread area of the Michelin Yieldbib radial tire, complete with a two-year free replacement Stubble Damage Warranty and VF high carrying capacity.

Due to Michelin standard rubber compounding and stubble deflecting sweeping 45 degree R-1W design, even our standard tires without Stubble Shield offer excellent stubble resistance compared to others.

In summary, the first and lowest cost approach to reduce stubble is to purchase the right tire, with the right rubber compound and right sweeping 45 degree lug design. As a backup plan, if your stubble damage is persistent, a mechanical device may be a sound investment. Farming efficiently and profitably should be top of mind. Your tires shouldn’t need to be.

Firestone Ag

Bradley J. Harris:  Manager, Global Agricultural Field Engineering

As a farmer myself, I see crop stubble becoming more and more of an issue for tires. In the past, it was common to get complaints from growers about driving over corn or cotton stalks resulting in tire punctures.  As crop genetics improve and growers focus on agronomics, additional crops like soybeans and cereal grains are now leading to tire damage.  Growing up, Grandpa and Dad would drill soybeans at a population rate of 200k to 220k, and the stalks would have a maximum stalk diameter of 3/16”.  Today, agronomists are suggesting rolling back those seeding rates to allow the soybeans to bush out.  When I measured the stalk diameter of a soybean field planted at 140K population rate, the diameter ranged from ¼” to ½”.  (See picture 1, which shows the stalk diameter of 7/16” from a 2018 soybean plant.  The larger diameter stalk means a better stand at harvest, but it also causes more damage to tires.

STALK DIAMETER Pic 1

When customers have stubble issues, the common assumption is that the tire’s tread rubber is softer or under-cured.  To get into the science of tires, tire manufacturers measure tread rubber hardness with a tool called a durometer (See picture 2).  The typical agricultural tire rubber hardness ranges from 66 to 74 units.  This level of hardness is required to allow the rubber to flex over different terrains and with different inflation pressures. Firestone has measured crop stubble in the field and it can range between 80 to 110 units.  The hardness of the soybean plant we measured, which had a stalk diameter of 7/16”was 90 units.  When a softer material makes contact with a harder material, the softer material is damaged.  Tire manufacturers are working on a solution, but at this point in time there is no solution.  Yes, a harder tread compound could be used to help reduce stubble damage, but the harder tread rubber could cause decreased tire performance because the harder rubber would have less flex.  It is a balancing act for tire engineers, and until a solution is identified, tire companies encourage customers to find mechanical ways in their operations to manage the stubble.

DUROMETER MEASUREMENT Pic 2

Stubble can be managed in a variety of ways, from something as simple as not driving directly over the stubble, to installing a stubble-deflecting device.  I encourage customers with stubble problems to install stubble prevention equipment on the corn head or platform to push the stubble down while harvesting.  If the customer cannot install stubble deflectors on the heads, there are nice stubble deflection devices that attach to the front of a tractor.  Customers do not have to spend a lot of money on stubble deflection devices, the device can be custom made.  Firestone Ag does not recommend one system over another; the main point is to consider a deflector because it pushes the stalk over, helping to keep the stubble from coming into direct contact with the tire. If you are interested in looking at stubble protection solutions, we recommend talking to your local tire dealer or implement dealership.

If your tires do have stubble damage, they likely can remain in service unless the tire’s body ply or tread ply cords are exposed. The tires in pictures 3 and 4 have stubble damage, but it is just cosmetic. The interior construction is undamaged and the tire can remain in service.

Stubble Damage WHEAT Pic 3

Stubble Damage SOYBEANS Pic 4

If a customer is in the market for new tires and has concerns about stubble damage, they should ask the tire dealer about the tire’s stubble protection policy.  Stubble damage is typically not considered a warrantable condition by most tire companies.  However, Firestone Ag, along with other tire companies do have a stubble damage policy.  This policy is different from the tire manufacturing warranty and the coverage is not as long.  Your tire dealership should be able to explain different coverage options.  I also encourage customers to avoid running brand new tires in heavy stubble conditions.  If your operation is planning to install new tires on equipment, I suggest installing them after the planting or harvesting season.  Giving the tires extra time to sit before use allows the processing waxes to migrate to the exterior of the tire.  As these waxes move, a tire will slightly harden by 1 or 2 points.

Again, there is no perfect solution for preventing stubble damage on tires.  Ag tires are going to operate in conditions that will expose them to the potential of stubble damage.  Taking the correct measures in your operations to minimize the exposure to damage by using stubble deflection devices or not running directly on stubble will help your operation minimize stubble damage.

*Additional Thanks to Kelsey Jo Oechsle at Lankota for providing the stubble deflecting device picture.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

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James Tuschner <![CDATA[Proper Tractor Ballast: MANUFACTURER’S ANSWER]]> https://agtiretalk.com/?p=1079 2018-10-17T01:19:37Z 2018-08-22T03:59:59Z  

BKT USA, Inc.

Dave Paulk:  Manager Field Technical Services

There are several important reasons for using ballast on tractors. Tractors and combines often have to add weight to accommodate horsepower imbalances. Adding weight where required will improve traction and reduce slippage. Managing the ballast and tire inflation pressures can maximize traction, minimize compaction, increase the life of the tractor drivetrain, and increase productivity. Adding ballast to a tractor is an effective way to get the power of the tractor to the ground.

There are general guidelines for ballasting a tractor based on the type of equipment being used. A Mechanical Front Wheel Drive (MFWD) tractor should weigh 120-145 pounds per PTO horsepower. 130 pounds is a common weight used per PTO horsepower. The weight split should be 35-40% of the weight in the front, and 60-65% of the weight to the rear. Some manufacturers recommend a 35-65% weight split as it makes it easier to control power hop.

A 4 Wheel Drive tractor should weigh 85-125 pounds per engine horsepower. A general recommendation is a 60-40% split, with 60% of the weight in the front. 120 pounds is a common weight used per engine horsepower. This could change some due to the type of implements used. As in the case of the MFWD, power hop can be controlled by moving some weight from front to rear based on the equipment used. Implement dealers have calculators to best determine weights and weight splits based on the type of equipment being used and recommended by the manufacturer.

Cast weights and liquid can be used to ballast tractors. Both have pros and cons. Cast weights on MFWD’s and 4 WD’s are easier to work with if power hop becomes an issue. Cast weights are the most convenient and can be changed according to ballasting needs. Fluid is more economical than cast weights, but fluid is harder to change. When adding or removing ballast, the proper weight distributions should be maintained for the tractor type.

Once MFWD tractors are set up with the proper weights and distributions, they can basically use any type of implement without having to change weight distributions. The exceptions could be heavy implements on the three-point hitch or implements that place large loads on the drawbar such as rippers. These lighten the front end and may require more front weight.

On 4 WD’s for towed implements, a 55-45% split (55% front and 45% rear) would probably be near ideal as this helps to control power hop. As the drawbar load dramatically increases in downward pressure, the weight splits need to move back to around 60-40% for optimum performance.

There are potential problems that can be discarded by the correct tractor ballast. If tractors are under ballasted, there is too much slippage. 5-15% slippage is considered in the normal range with 8% slippage considered optimum. Too much slippage effects fuel consumption, field operating time, and tire wear. Over ballasting also has a potential for problems. This can cause tire failures by tires slipping on the wheel, and lug cracking. It can also cause drivetrain problems, increase soil compaction, and reduce efficiency.

Air pressure in the tractor tires also greatly affects soil compaction. The heavier the tractor, the more air pressure that needs to be used to carry the load. Increasing air pressure equals increasing ground pressure. By optimally ballasting a tractor, the correct air pressures can be used and thus reduce soil compaction.

Newer tire technologies are being used to further decrease soil compaction issues associated with heavier equipment. BKT makes the Agrimax Force for high horsepower tractors in an IF version. The IF will carry 20% more weight at the same air pressure as a standard tire. BKT also produces the Spargo in a VF version for tractors and sprayers. The VF will carry 40% more weight at the same air pressures as a standard tire.  BKT is constantly developing tires with the latest technology to keep up with the ever-changing agricultural market.

Alliance Tire Americas

James Crouch:  National Product Manager—Agriculture

It takes a certain amount of weight for a tractor to transfer one horsepower of energy from the engine to the ground—figure 130 to 140 pounds per PTO horsepower for front-wheel assist (MFWD) tractors and 95 to 110 pounds per PTO horsepower for 4WD tractors. That often requires a little extra weight, which is called ballast.

If you have too little weight, your tractor isn’t working as efficiently as it should. Your slip increases and you just aren’t getting all the power you paid for when you bought that machine. If you have too much weight, your soil compaction increases and your fuel efficiency can be reduced. And if the weight is poorly balanced, you can lose efficiency and experience power hop.

Liquid ballast in the tire is a popular way to add weight to the tractor. However, we design tires to be filled with air, not liquid. So when you add liquid to a tire, you’re reducing the tire’s flexibility and performance, and deforming the shape of the tire. That can lead to irregular wear in the center of the tread, a harder ride, and significantly reduced sidewall flex. From a performance perspective, you’re turning a radial tire back into a bias.

The bottom line is that if you’ve paid good money for horsepower, proper ballast is essential to make sure you’re getting your money’s worth. And if you’ve invested in radial tires, that ballast should really be achieved with cast iron weights so those tires can perform the way they were designed to. That way, you get the most out of your tractor and your tires.

Continental Agriculture North America

Harm-Hendrik Lange:  Agriculture Tires Field Engineer

The right ballasting for tractors depends on many factors. Generally speaking though, the tractor should be as least ballasted as possible, if the ballast is not really needed. Each pound that needs to be moved forward needs energy during acceleration, creates more energy during braking, creates a longer stopping distance on average, and creates more soil compaction during operation on wet soil conditions.

However, there are certain applications and operations where ballasting is needed and reasonable. Those situations can be clustered in two main topics:

  1. To prevent an unbalanced situation on the tractor, e.g. when working with a heavy front loader and adding ballast in the rear hitch or on the rear axle, or when using a front ballast as a counter weight for a heavy rear hitch. With higher loads on one end, the maximum speed may be reduced for both the axle and the tires. Ballasting can help counter this unbalance to lessen the need to lower speed.
  2. To make the tractor heavier to transmit more force to the soil, e.g. for implements with lower working speed like a plow where the operational speed is less than 6 mph. Here, all the engine power is transformed into a high torque on the axles, which means high forces in the contact patch between tire and soil. In this instance more weight means better grip for force transmission to the ground – so basically the weight supports the tire.

Continental Recommendations for Proper Ballast 

Michelin Ag

David Graden: Operational Market Manager – Agriculture

Ballasting a tractor is the long time practice of adding weight to a machine for the purposes of counter weight to an implement, increasing traction, torque transfer, etc. There are many different ways to add ballasts; fluid in the tires, wheel weights, suitcase weights, ballast box, and more. In many cases, this is a guessing game for producers. Typically, I encounter machines with less weight than necessary to transfer the torque for that specific machine. In even more cases, not only does the machine not have enough weight, but most of that weight is on the rear axle. This would be an improperly ballasted machine.

Depending on the machine’s use, improper ballasting will cost more time and money than most would expect. Fluid in tires, for example, is a very common and cost effective method of ballasting a machine. Unfortunately, the end result here is a tire that does not flex and, therefore, not able to perform as it was intended. Despite the achievement of adding weight and the perceived increase in traction, this stiff tire now has a much smaller footprint than it would if it were properly inflated. A smaller footprint means less traction. Less traction equals higher slip, more fuel consumed, greater soil compaction, rougher ride, and ultimately a very negative effect on yield.

On the flip side, however, adding wheel and/or suitcase weights or a ballast box, you could achieve proper weight distribution for your machine and its horse power. As a direct result, you would gain better fuel economy, ideal slip, less soil compaction, a better ride, and increased yield.

At Michelin, we strongly encourage producers to work towards proper weight distribution of their machine. In many cases this can be costly; however, we can work with the current weights on the machine and air pressures to transfer as much torque as possible. Each Michelin field representative is equipped with a set of tractor scales and the knowledge to calculate proper weight distribution to efficiently transfer the machine’s maximum torque to the ground. This should be an all-encompassing solution to maximize traction (which reduces slippage and soil compaction), torque, and fuel efficiency, minimize power hop and road loping, and overall productivity.

Further, it is very important to keep in mind each task and corresponding implement can require different ballasts and tire pressure recommendations. For instance, a front wheel assist machine requires about 120 lbs per PTO Horsepower at 6 mph to fully transfer the torque. Additionally, of the total machine weight, 35% should be on the front axle and 65% should be on the rear axle. Let’s say you add a hitch mounted strip till on the back. Adding this equipment just changed the entire calculation. Now, you have to take into account the weight of the implement, while working in the field, and adjust your ballast weights and air pressures accordingly.

Finally, this change only occurs a handful of times per year. Investing in ballast weights that allow you to change quickly and easily will give you the ability to properly distribute your machines weight for every season. Coupled with the proper air pressure, you will maximize your overall productivity!

Maxam Tire International

Mark Turner:  Senior Product Marketing Manager, Agricultural Tires

Ensuring you are using the correct ballasting weight is not always an easy exercise but ultimately it is one that is worthwhile. Unnecessary extra weight or not enough weight can both lead to higher fuel consumption as well as possible uneven tire wear and thereby increase input costs.

Correct ballasting for field work is entirely about ensuring that slip rates are kept in the best window that allows optimum tractive efficiency & drawbar pull.

Typical recommended rates of slip are 10-15% for 2-wheel drive tractors (2WD) and 8-12% for 4-wheel drive (4WD) or mechanically assisted 4WD tractors (MFWD).

Too much weight can, in addition to using more fuel, mean not enough slip resulting in soil structure damage and possibly over stressing of transmission components.

Too little weight results in slip rates that are too high which can mean longer time is required to finish the work and can also lead to excessive fuel consumption.

It is worth remembering that soil compaction in the top 12 – 16” (30-40cm) is primarily a function of the tire pressures, below this level, compaction and structural soil damage is related to total vehicle weight. It is easy to see why correct ballasting that allows efficient traction and enables good speed across the ground is a major contributor to soil health.

The best type and weight of the ballast should be assessed for each implement used and should be added to the front and / or rear to ensure optimum weight distribution between the 2 axles.

The general recommendation for field work is to make sure that at least 20% of the total weight is on the front axle, this ensures good steering response and vehicle control as well as limiting the possibility of an adverse reaction between suspension systems and automatic draught controllers.

For prolonged road work applications, a weight split of around 40% front and 60% rear should ensure good vehicle stability and control as well as ensuring that dynamic overload is not excessive when the vehicle is braking.

It is also important to remember to alter your tire inflation pressures to suit the new load on the tires when weights are changed.

Although it can be a time-consuming exercise, getting your ballasting right is an important tool in helping to optimise your input costs, soil health and wear and tear on your tractor.

Trelleborg Wheel Systems

Norberto Herbener:  OE Applications Engineer

The tractor market has been evolving to larger and heavier units, with more power and more efficient transmissions, allowing for faster and more precise work in the field. However, farmers are considering the effects of soil compaction on crop health and yield in their buying and management decisions more often. Tire selection and tire management have not evolved in the same way, even though tires are the “link” between tractor and soil. There is no recipe that fits all situations as there are many factors to consider including varying soil types and conditions, implements used, working speed, tractor type and weight, etc.

It’s a given that for the same weight tractor, a larger footprint on the soil (contact area between tire and soil), represents a lower superficial compaction of the soil (area where most of the roots develop). On the other hand, the higher the flotation, the lower the traction (less depth of the lugs in the soil) and vice versa. To make it a bit more complicated, the tractor needs a certain amount of weight to transmit power to the ground –which increases soil compaction.

Given these dynamics, incorrect weight to power ratio, weight distribution, tire inflation pressure, tire size and footprint area for the application, can create lower efficiency and issues like power-hop, rim to tire slippage and tire to soil slippage.  For a tractor to perform at its peak capabilities and efficiency, consider the following points.

The first point is the correct weight and weight distribution that the tractor must have to transfer power with efficiency. As a rule of thumb, a correct weight ratio begins considering that between 100 to 120 lbs. per horsepower of the tractor is needed. Therefore, a 300 hp tractor should weigh approximately 30,000 to 36,000 lbs. This weight will allow the tire lugs to penetrate the soil deeply enough to create optimum grip and acceptable tire to soil slippage. The best way to increase a tractor’s weight is by adding solid ballast to the axles or on the tractor chassis. Adding weight by filling tires with liquid ballast is not recommended as it reduces the ability of the tire to flex, can cause corrosion of the rim and creates additional inertia on the wheel when moving.

The second point is weight distribution. Once the correct tractor weight is defined, the distribution should be 50% on the front axle and 50% on the rear axle for 4WD. For a front wheel assist tractor, the distribution should be between 40-45% on the front axle and 55-60% on the rear axle. If the design of the implement creates a high load on the rear axle (reducing the load in the front axle), the ratio on front wheel assist tractor should be closer to 45-50% in the front and 50-55% in the rear. For 2WD tractors the front axle should have between 25-35% of the total load. It is very important to measure this weight per axle with calibrated scales (individual per tire or per axle, like on a grain elevator scale). An incorrect weight distribution can create issues like “power hop” where the front axle is too “light” (losing traction) and the rear axle is overloaded creating excessive “grip.” When a customer has power hop issues, it’s a clear indication that the total tractor weight and/or weight distribution is not correct for the application. This issue can be fixed by correcting the ballasting without the need to change tire size or tire ratio.

The third point is tire inflation pressure. Each tire’s size load capacity changes with inflation pressure changes –the higher the inflation pressure (more air volume in the tire chamber) the higher the load capacity. This load capacity is defined by the type of tire (bias, radial, IF, VF, IMP etc.) and design (width, rim diameter and ratio), and is regulated by the TRA (Tire and Rim Association) in the US or the ETRTO (European Tire and Rim Technical Organization) in Europe. These two entities also specify the load capacities for each tire at different inflation pressures and in some cases working speed (this is not the case for IF and VF tires where the load capacity is independent of speed) to create “tables.” These tables allow the user to locate the correct inflation pressure when the load applied to each tire and the speed where this load is applied are known. If the tire is underinflated it can be damaged, i.e. slippage between rim and tire causing bead damage, etc. If the tire is overinflated it will reduce footprint, reduce traction (less lugs on the ground) and increase compaction. Using the correct inflation pressure will ensure the best performance, largest footprint, best traction and lowest compaction.

A note related to minimum pressure – even if the load is low enough to allow for very low inflation pressure (below 10 psi), the minimum inflation pressure should not be below the 10-12 psi mark. Below this pressure value is risk of rim to tire slippage (especially with high horse power tractors in extreme torque applications, i.e. earthmoving) as there is less pressure from the tire bead against the rim flange, reducing the efficiency of power transmission from the tractor to the tire.

Once these three steps are followed, the tractor should perform to its peak capabilities and efficiency. For further applications, steps one and two would not change substantially –only if the implement used is creating a dramatic change in “down force” on any of the axles, where a new calculation should be performed and checked for the required changes. The tire inflation pressure should be checked often, as tires that are not 100% air tight over longer periods of time and loss of air pressure will occur over time, also known as “air pressure bleed.” If there is not much change on the use of the tractor (implement used, working speed etc.), a minimum preseason pressure checkup is recommended.

Another last point to consider is the size of tires chosen for the tractor and the effect on the inverse relation between tractive efficiency and flotation-compaction. The larger the tire size, the larger the contact area between tire and soil (desired), lower superficial soil compaction (desired) and lower power transmission (not desired) due to less lug penetration. In the opposite way the smaller the tire, the smaller the contact area (not desired), higher superficial soil compaction (not desired) and higher power transmission (desired) as the lugs penetrate more deeply. Some sizes will be a given due to limits on equipment, limits on width and height of the equipment, tractor use (like row crop usage), but when we can choose the size, there will be a fine balance and trade-offs between soil compaction and power transmission.

CEAT Specialty Tires Inc. 

Jim Enyart:  Technical Manager

Ballasting has been utilized for equipment functionality and stability as well as transferring power to the ground. Many types of ballasting materials have been utilized including rocks, soil, cast iron, water, calcium chloride, magnesium chloride, beet juice and more. These options have advantages as well as disadvantages. Some are relatively cheap while others are expensive. Some are environmentally friendly and others not so much. Some have lots of versatility while others are not. The choice of ballasting materials includes many factors but the most critical aspect of adding ballasting is how much weight to add and where to place these materials.

Agricultural and construction equipment with buckets or lifting forks have massive cast iron counterweights built into the design of the machine to provide functionality. Agricultural tractors have optional wheel, axle and suitcase weight packages to address total weight and the weight distribution that is critical to optimum performance.

We will address ballasting as it applies to farm tractors. The first critical factor is knowing the engine horsepower of the tractor and the axle weights. Ideally, the weight per horsepower ratio should be between 100 and 120 pounds/hp. The lighter weights are more desirable and efficient as long as there are no performance issues such as stability or wheel hop. Increased weight ratios may be utilized to reduce slip which increases efficiency especially in demanding applications.

The weight distribution is extremely important. For 2-wheel drive tractors the weight distribution should be 30% on the front axle and 70% on the rear. MFWD tractors should have 35% on the front and 65% on the rear axle. Four wheel drive tractors should carry 60% on the front and 40% on the rear axle. Allowances for additional weight due to attachments should also be calculated into your weight distribution adjustments. Wheel weight, axle weight and suitcase weight packages are utilized to obtain the correct weight total and distribution. Additional weight adjustments should include weight packages as the first option. Keep in mind that for optimum performance, the weight required often changes with the implement that is carried by the three point hitch or pulled with the draw bar as well as the application. Maximizing versatility with weight adjustments should be a major consideration. Adding liquid ballast into the tire’s air chamber is the least desirable. Liquid ballast reduces performance due to inhibiting the deflection of the sidewalls of radial tires. Liquid ballast is less versatile but may be utilized as part of your weight distribution program.

Air pressures should be set just above the maximum load carrying capacity you are expecting from your tires based on the most demanding application. The calculated air pressures for roading are quite different from operational pressures for field work. Changing air pressures between road and field usage is time consuming and usually not practiced. Air pressures should be set for the road application due to the higher speeds which is the most demanding from a load carrying aspect. Under inflating tires will damage the tires and eventually lead to failure. Tires are too expensive to risk failure from under inflation for any of your applications!

Correct weight distribution and overall weight totals are key to maximizing tractor performance and transferring power to the ground.

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)

Scott Sloan:  Ag Product Manager / Global LSW

Just like inflation pressures, making sure you have properly ballasted tractor will make it much more efficient when it comes to machine field performance.  This doesn’t only include large tillage tractors but also ballasting is used on smaller utility tractors to help improve safety when using front-end loaders or three-point mounted equipment, such as mowers or sprayers, or when operating on sloped ground. Whether running in heavy tillage or moving heavy hay bales, the correct ballast is important.

Fact is, too much weight can cause a tractor to feel sluggish, increase soil compaction, reduce fuel efficiency and result in premature drivetrain wear.  Too little weight can result in tire slippage, reduce fuel efficiency and cause premature tire tread wear.

Proper ballasting can be complex but there are many resources available online or even your tire dealer to assist with ballasting tractors. The end game is trying to minimize tire slippage when you head to the field.  Between inflation pressure and ballasting you will have your tractor performing at its most efficient.  Most manufacturers shoot for slip in the 8% to 15% range.  Anything over that is extremely noticeable and not very efficient.  Growers feel they are sending a lot of money with little return though the exhaust stack.  Most growers I deal with do prefer to be running in the 3% to 9% range.

So a quick fast approach to get in the ballpark for example on a 4WD depending on the application to have anywhere from 85lbs to 125lbs per rated horse power.  For instance, a 4WD rated at 500hp should be in the 50K to 55K total weight with 55%-60% on the front and 40%-45% on the rear.   Not only is the total machine weight important, the distribution of that weight is just as critical.  The table below is a quick reference to proper ballasting and weight distributions

At the end of the day, each grower needs to understand the factors involved and the objective for their individual operation.  One end user may be okay with a little more slip and a lighter machine, while the other wants to pin all the power to the ground.  Trial and error with an understanding of these factors and patience to experiment with different ballast packages will result in a well optimized tractor performing at the highest efficiency.

Firestone Ag

Bradley J. Harris:  Manager, Global Agricultural Field Engineering

To get the most efficiency from a tractor it’s critical to have the proper amount of ballast and the weight appropriately split between the front and rear axle. There are some general rules that tractor and tire manufacturers use when helping customers set up tractors used for fieldwork.  These guidelines help make sure there is enough weight on the tractor to transmit the horsepower to the ground, while making sure the tractor is not so heavy that horsepower is wasted trying to move the tractor.  To properly set up a tractor, a short five-step procedure can be used:

Step One: Identify the horsepower rating of the tractor.  For 2WD and mechanical front wheel drive (MFWD) tractors, the rated PTO horsepower is used.  For 4WD tractors, the tractor’s rated engine horsepower is used. For the following calculations, we will use a MFWD tractor with 180 PTO horsepower being used to pull drawbar implements as the example.

Step Two: Calculate the target total tractor weight.  The target tractor weight is based on the driveline of the tractor.  Chart 1 has the target weight per horsepower for the three types of tractor.

 

 

 

 

Chart 1: Weight per horsepower recommendations

Example Target Tractor weight: 180 PTO HP x 130 LBS/PTO HP = 23,400 lbs.

Step Three: Calculate the recommended front and rear axle weight splits.  Just like determining the tractor weight, the weight split is based on the tractor type and how the tractor is being used.  Chart 2 has the target weight splits, according to standard industry practices. Keep in mind these are all target weight splits with no equipment mounted to the tractor.  If 3-point equipment is being used, make sure there is enough weight on the front axle to keep the front axle on the ground.

 

 

 

 

 

Chart 2: Weight Split Targets

Example Tractor Weight Splits:
Front Axle 35%: 23,400 lbs. x 0.35 = 8,190 lbs.
Rear Axle 65%: 23,400 lbs. x 0.65 = 15,210 lbs.

Step Four: Weigh the tractor.  The most accurate way to find the weight is to use a scale. This can be done on a platform scale or on portable scales. When weighing a tractor, make sure all the fluids are topped off, especially the fuel tank.  If for some reason the tractor cannot be weighed, please consult your operator manual or your equipment dealership.  With most newer tractors, the manufacturer has a procedure to calculate the tractor weight based on the base tractor and the weight package on the tractor.  If aftermarket items (Saddle tanks, loaders, etc.) are added to the tractor, I recommend using a scale.

Example Tractor weighed with portable scales:
Front axle: 10,150 lbs.
Rear axle: 15,500 lbs.

Step Five: Add or remove weight.  In most cases a tractor cannot be ballasted to the exact target weight outlined in Chart 2.  In the example, the target front axle weight is 8,190 lbs., but it weighed 10,150 lbs.  Let’s assume the example tractor has six front suitcase weights.  Since the front axle weight is heavier than the target weight, we would remove the suitcase weight and re-weigh the front axle.  Even though the suitcase weights are 100 lbs., they add 130 lbs. to the front axle because the weights are in front of the axle.  When the weights are removed, the tractor is weighed and the new front axle weight is 9,370 lbs.

Step Six:  Set the inflation pressure of the front and rear tires.  Now that the front axle and rear axle weights are known, we can use the tire inflation tables to look up the minimum inflation pressure required to carry the load.  To help customers with setting correct pressures, most tire manufactures have free tire inflation pressure calculators on their websites or as an app.  On FirestoneAg.com, there is a new inflation pressure calculator to help determine the recommended inflation pressure. With these calculators, all the customer needs to do is select the type of equipment being used, select the tire setup (singles, duals, triples), enter the tire size, and input the axle load.  The calculator will determine the minimum inflation pressure required to carry the load.  In this example, the front tires were 420/90R30 used as singles.  The minimum inflation pressure to carry the 9,370 lbs. is 17 psi.  The rear tires were 480/80R46 used as duals.  The minimum inflation pressure to carry the 15,500 lbs. is 12 psi.

When the tires are inflated to the recommended inflation pressure, the tire is able to develop the proper footprint. Proper inflation pressures allow the tire to develop the maximum traction, minimize tire wear and allow the tire’s sidewall to flex without causing damage to the tire.  If the inflation pressure drops below the minimum recommended inflation pressure, the tire will over deflect, or squat more, which will cause internal damage or faster wear.  However, over-inflating tires (even by 10 to 15 psi) will reduce the footprint size, reducing traction and increasing soil compaction. To get the most performance out of a tire, it is so important to check tire pressures daily when using the tractor.

If a tractor’s setup doesn’t change, and the tire configurations stay the same all the time, the axle weights and recommended inflation pressures will not change on the tractor.  But if the duals are removed on the rear axle, the inflation pressure on the inside tires needs to increase to 23 psi to carry the 15,500 lbs.  If the tractor is going to pull a 3-point ripper, it is necessary to weigh the tractor with that 3-pt ripper attached to the tractor to get accurate axle weights.  Those new axle weights should be entered into a tire inflation calculator to find the new minimum inflation pressure.

Tractor setup and setting the tire inflation pressure is not a hard job, but it does take time to properly determine the weight needed on the tractor. Weighing the tractor, using tools like a tire inflation calculator to determine the recommended inflation pressure, and using an inflation pressure gauge to check the pressure are easy ways to remove the guesswork and increase efficiencies in the field.

 

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James Tuschner <![CDATA[AG Tracks vs Tires: Manufacturer’s ANSWER]]> https://agtiretalk.com/?p=1026 2018-10-17T01:18:28Z 2018-08-02T05:35:30Z  

Firestone Ag

Bradley J. Harris:  Manager, Global Agricultural Field Engineering

Just like asking if apple or orange juice is better, asking if tracks or tires are better systems comes down to customer preference. Both systems have pros and cons, so it is important to understand the facts and benefits about each system and determine which is best for your operation.  In many operations, it could be a combination of both systems.

When I ask users why they have tracks, the number one response I get is, “I want to get rid of compaction and the track has a much larger footprint area.” While it is true the total footprint area of a track is larger than a tire, the weight of the machine is not equally distributed under the track. When measuring the contact pressure of the track system, there are pressure spikes under each one of the boggy wheels. In wet or moist soils, the soil is damaged by the highest contact pressures, which would be under those boggy wheels. Firestone Ag has conducted studies on soil contact pressures on two and four track systems and wheeled tractors and has published technical papers with the American Society of Agricultural and Biological Engineers (ASABE). The results show:

  • If the inflation pressure of the tires is less than 20 psi, tires transmit less contact pressure to the soil compared to tracks.
  • From 20 to 35 psi, the tracks and wheel systems were comparable.
  • If the inflation pressure of the tires are above 35 psi, the track system had lower contact pressure than the tires.

However, there is still the perception that tracks reduce soil compaction when compared to tires, in all situations. What we have heard, anecdotally, is that the absence of a rut in the field means there must be no compaction. In wet soils, it does not matter which system is being used – compaction occurs with or without ruts. The rutting is a function on how the wheel and track system operate differently. A tire rotates and the tire lug needs to pull the tractor forward. The rotation of the tire causes a wave in front of the tire, and the tire is climbing out of the rut in wet soils. The lug on the track system is planted in the soil and the tractor is pushed forward. With the track system there is not a wave of soil, so the track lug isn’t trying to climb out of a rut.

When looking at traction, track systems are most efficient at 0 – 3% slip while wheeled systems are most efficient at 5 – 9% slip. The lower slip range of the track system does give users more traction in the field, but that does not result in less fuel used. A track system takes more horsepower to rotate the track, which results in higher fuel consumption. When comparing a tracked tractor to a comparable wheeled tractor with the proper inflation pressure, they both will use similar amounts of fuel to complete a task.  If the tires on the wheeled tractor are over inflated, that tractor will not develop the proper footprint, which results in less traction. In this scenario, a tracked tractor would use less fuel. For traction and fuel usage, both tractors will have similar fuel costs.

When transporting tractors on the road, a wheeled tractor can operate in the 25 to 30 mph range, while tracked machines are limited to 20 mph. The faster road speeds are better for minimizing wasted time between fields. However, the narrower width of a tracked tractor makes driving on the road less stressful compared to a 4WD tractor with duals, especially in areas of the country where roads may only be 15 feet wide.

The last item a customer should consider would be total cost of ownership. Typically, a tracked tractor will cost more to purchase versus a similarly equipped wheeled tractor. Both systems require regular maintenance during the life of the tractor. For a tracked machine, it is important to make sure the track tension is set correctly and boggy wheels are greased or oil levels are maintained. On wheeled tractors, the inflation pressure must be set based on the axle load and maintained when operating the tractor. If the tractors are driven over abrasive stubble (corn or cotton), both tracks and tires will experience stubble damage. The track system has an advantage of not going flat because of punctures, but exposing the steel in the tracks still requires replacing the tracks, just like seeing the cords in a tire.

In the end, it comes down to what system works for a farm. Both systems will work similarly in most situations. If a farm is width-restricted or needs to operate in wet soil conditions, a track system may be the best fit. If an operation wants to minimize upfront costs and is able to match axle load to inflation pressures, the wheeled system may be the best fit. Remember that compaction will occur in wet soils regardless what kind of system is running. Firestone Ag has experts and engineers available to help customers understand the pros and cons of both systems, as well as what Firestone products will work best in either system.

Michelin Ag

David Graden: Operational Market Manager – Agriculture

Throughout my travels across North America, in all types of farming environments and soil types, I like to ask track owners their thoughts and how they justify the additional expense for track machines. In all but one instance that I can recall, the owner will drill down to, “its’s my insurance policy,” meaning, their tracks give them the perception of superior traction, pulling power, and/or flotation (which is commonly confused with the reduction of soil compaction). A grower in central Iowa told me tracks require less effort to guide straight down the rows. But at what cost?

Tracks have only one advantage over tires:  traction in very wet soil. In these conditions, however, their impact on the soil, in terms of compaction, does the most damage. A Machine fitted with Michelin VF tires at proper air pressures has very comparable traction- with reduced compaction. With Michelin’s recent acquisition of two CTIS (Central Tire Inflation System) companies, PTG and Teleflow, the playing field has begun to level out. Additionally, although all Michelin tires perform very well with CTIS, we have brought a new VF Axiobib and VF Evobib to the market, specifically marked as “Tire Inflation Ready,” designed to be used with CTIS. Now, instead of setting air pressures for the machine’s highest carrying capacity at the fastest speed, the user can set multiple air pressures. In some cases, this means 6 psi in the field is an option with just the push of a button. In turn, with these CTIS ready tires, traction is maximized with minimal costs compared to the purchase and maintenance of a track machine. The next question to ask is at what point is the soil too wet? Have you ever seen a track machine sink in the middle of a very wet field? Many of us have!

Fuel Economy is another major disadvantage of tracks. Have you ever watched and listened to the exhaust stack of a quad track as it pulls a large implement through the field? The amount of fuel these track machines can consume over a short distance is incredible! For every 100 Hp of power transmitted, tracks can only deliver about 70 Hp, whereas tires will deliver up to 90 Hp. Additionally, when a machine is fitted with pneumatic tires vs tracks, a comparable machine weighs about 3 tons less with far fewer moving parts/mechanisms, requiring less energy to move the tire machine forward. Pneumatic tires will transmit up to 29% more power to the ground and are 4 times better at overcoming rolling resistance, making that power available for use elsewhere (i.e. fuel savings).

When Roading, track machines are typically limited to the speed in which they can travel roads based upon the width and length of the track they are running. You will usually find a manufacturer recommends a top speed or the machine is governed to prevent damage to the tracks. Due to the amount of movement from bogie wheels and the mechanisms required to move the machine on tracks, heat builds up in the rubber of the track. The downward force/weight of each of these will also cause the rubber to deform/move. The more rubber squirms, compresses, decompresses, the more kinetic energy builds up and creates heat. Heat and rubber do not mix well and ultimately causes the rubber to break down.

We believe Soil Compaction is the greatest of all costs associated with tracks; especially in very wet soil. In fact, tests have shown tracks have a significant difference in how ground pressure is applied. Tracks apply a very non-uniform pressure, while tires, specifically IF & VF tires, apply a very even/uniform pressure. In fact, each roller (on a three roller track per the example) can apply as much as 50% more ground pressure, which translates to deep compaction.

To be clear, tracks have a market, and depending on the region, farmers may want to achieve different results. However, for most of North America, when you add the initial financial cost, fuel cost, maintenance, lower yield due to soil compaction, and less efficiency on the road, choosing tracks over properly inflated IF or VF tires is a very costly “insurance policy.” In the end, what are you trying to gain?

Alliance Tire Americas

James Crouch:  Marketing Specialist

At Alliance, we have invested ourselves completely in the development and sale of pneumatic agriculture tires because that is what we believe is the correct solution for providing the best overall performance for farm equipment.  Sure, there are applications and field conditions that may lend themselves to belts, but the upfront cost as well as the maintenance costs make it tough to justify even in those conditions.

We are continuously expanding our Agriflex line to provide the optimal solution for farmers.  Our Agriflex product offer consists of our IF and VF products which are the best available in reducing compaction and maximizing traction.  A properly inflated VF tire will give any track system a run for its money.

To maximize the benefit of VF technology, or even standard radials, the tires must be run at the correct inflation pressure.  The more a tire is overinflated, the lesser the potential performance will be.   As a tire increases past its optimal inflation pressure, the footprint gets smaller both in length and eventually in width, while a properly inflated tire will provide the largest footprint available for that sized tire.  Footprint is often where people assume a track has an advantage.  This may not be completely true.

A pneumatic tire, when inflated properly, will evenly distribute the load of the machine throughout the contact area or footprint.  This even weight distribution minimizes the damage done to the soil.  Tracks are not known for their even weight distribution and instead provide high pressure spots under the idlers or dollies that cause what is known as deep compaction and assist in the creation of hard pan deep under the surface.

Since their spike in popularity, tracks have been researched extensively to try to better understand what actually happens under them in relation to that of a tire.  Research from the University of Minnesota supports the theory that a properly inflated tire will offer less compaction than a track.

University of Minnesota Study https://www.extension.umn.edu/agriculture/soils/tillage/tires-traction-and-compaction/

Versatility is another strong benefit of tires over tracks.

One of the driving forces in Alliance’s R&D program is creating tires that can tackle any challenge—creating the right tire for the job. Tracks are basically a one-solution approach. In rubber tracks, you’ve got your classic lug or some minor variations that are very close to that theme. In steel tracks, you’ve got perpendicular grousers. Period.

If you search out the right tire, you can find plenty of options—thousands of them. Different combinations of width and height to get the footprint you want.  Sidewall technologies ranging from sturdy, stiff bias-ply sidewalls to VF sidewalls that extend your footprint and your load capacity even further. And tread designs that are optimized for different soil types or conditions, paved worksites, over-the-road travel, gravel and rock—literally every possible situation you may be running in.

Upfront and long term cost is another huge issue with tracks.  A new machine equipped with a four-track system will cost over 20% more than a machine with pneumatic tires.  This is an upfront cost that likely won’t be recoverable upon trade either.  When the belts wear out, the idlers will also likely need to be retreaded or replaced.

On a day-to-day level, it’s also important to note that optimizing inflation pressure to maximize performance is a simple task, and choosing the right tire is as simple as working with a knowledgeable tire dealer. So is changing a tire, something most farmers and certainly any dealer with a decent service truck can do in minutes. Tires don’t require the extensive (and expensive) undercarriage maintenance that track systems do.

The bottom line is that a new set of tracks will come with a significantly larger price tag than that of a brand new set of Alliance Agriflex+ VF tires.

Continental Agriculture North America

Rob Schultz:  Rubber Track Global Product Manager

As a broad portfolio provider, Continental offers both rubber track and tires for a complete agriculture solution. To help customers make the right product choice, we have a team of experienced field engineers who visit and consult with customers in the field, as every application is different.

Tires are suited for customers looking for an economic option with low purchase and maintenance costs. The low rolling resistance of tires also leads to lower fuel consumption and provides higher transport speeds than rubber tracks.  They have low heat buildup while roading and can be driven loaded and unloaded on both roads and fields, providing versatility in field and on road performance.

The carcasses of Continental agriculture tires are constructed with N.flex technology. The patent-pending material is flexible enough to absorb impact and then return to its original shape without permanent deformation. With tread patterns that have been engineered for efficiency, Continental tires can run on hard and smooth surfaces with high traction, meeting the challenge of smooth roads, rocky lanes, and muddy fields.

Continental Trackman rubber tracks, constructed for the most severe and extreme applications, provide the user more transfer torque to the ground, greater traction, and all with more flotation because of the larger foot-print. This foot-print allows the machine/equipment weight to be distributed across a greater area and lowers the ground pressure, thus reducing ground compaction equating to greater crop yields in most applications.

To improve track machine ride, we developed the guide-lug support system called ARMORLUG®, Anti-Vibration Technology® that reduces tractor vibration.  To reduce stubble damage, we have MAXXTUFF™ wire ply construction providing more ends per inch, and to improve traction, we have the patented ARMORLUG® ULTRA that provides 25% more torque capability than before.

Trelleborg Wheel Systems

Norberto Herbener:  OE Applications Engineer

There has been – and will be for a long time – the debate over which system is better “Tires or Tracks.” Both sides have advocates, both systems have advantages/disadvantages that will have a strong influence on the selection of one system over the other. Most important, this decision depends strongly on the use and soil conditions of each farm. We also have to consider the money the farmer obtains by selling his production and the cost of inputs needed to produce the crops.

The following points are what we know as facts:

  • Farm machinery equipped with tracks is more expensive than ones equipped with tires. So here is the first consideration when analyzing what system to purchase – Return On Investment (ROI) – “does my additional upfront expense really pay off with the advantages I could obtain using this equipment during it’s life cycle?”
  • Tires don’t have moving parts, but tracks have a lot of them. Moving parts means maintenance and wear. Depending on working conditions and the quality of maintenance this wear could increase rapidly.
  • The cost of a set of replacement rubber tracks is significantly higher than replacing a set of tires. This is particularly significant on harder ground, as lugs on the tracks are not as flexible as the lugs on tires.
  • Changing tread spacing or from flotation to row crop with tires is no issue. Track systems normally don’t allow tread spacing or track width changes, as the complete system must be changed.
  • Units with tracks are generally slower in transport mode than units equipped with tires. This is especially important for farmers with their farming ground spread out, traveling long distances between fields.
  • Track systems are heavier than tires, increasing the “death weight” the tractor must spend power without working, and reducing available horsepower for the real work.
  • Tires provide a smoother ride on hard surfaces or roads thanks to the cushioning the air inside the tires provides. On the other hand, tracks can provide a smoother ride on rough fields (specially when traveling across the rows). The tracks – due to their longer contact area – can bridge over ruts. However, when crossing ditches, waterways or small hills, this bridging effect of tracks is less adaptative than tires, reducing temporary the contact area, will teeter forward and drop down on top of the road surface or field.
  • Track tractors are more maneuverable at the end of the rows as they can counter-rotate, providing the possibility of a zero turn on the spot. This maneuver will create berming when turning on end rows and the farmer will need to level this area before planting (additional time-consuming labor). There is also the risk to jackknife the tractor into the implement when turning sharp on end rows with an implement that is hooked to the drawbar. There is more care and precaution to be taken with track units.
  • The flexing property of the tires helps improve the self-cleaning during labor in higher moisture conditions.
  • One large advantage of tracks is as they don’t have air, they can’t go flat like tires.

There has been a lot of discussion and studies about compaction comparisons between tires and tracks. Remember, there are two kinds of compaction. The superficial (what we see on the ground) is related directly to the pressure per contact area (total weight of the equipment divided by the contact area between soil and tires or tracks). The second compaction is the sub superficial (we don’t see because it’s beneath the ground) that is directly related to the weight per axle – independent of the contact area of the tires or tracks.

With superficial compaction, the general assumption is that tracks provide a lower superficial compaction as there is more surface contact with the ground compared with tires. This idea would be correct if the pressure (total tractor weight) was distributed uniformly on the complete contact surface of the track with the ground. Studies have shown, however, that this assumption is not the case and that the largest pressure occurs on the drive wheel and there is very little pressure applied in between the dolly wheels. With this in mind, and assuming that “if” a track has “X” times larger contact area as the comparable tire set on a tractor, the superficial compaction is “X” times lower – that’s not the case.

On the other hand, as the sub-superficial compaction is directly related to the tractor weight per axle and track tractors are heavier as tire tractors (a 4WD articulated tractor with tracks can be between 20-30 percent heavier than the tire version), track tractors are running with disadvantage related to the sub-superficial compaction

Last but not least (and the most controversial point of all) – which is more efficient in terms of traction and fuel consumption. This answer will be influenced directly by each point of view, soil type and condition, equipment in comparison, weight of the equipment, and equipment configuration. The only way to make a fair comparison is to have the same equipment (one on tires and the other on tires) correctly set up, on the same field and conditions.

BKT USA, Inc.

Dave Paulk:  Manager Field Technical Services

The debate between tires versus rubber tracks is ongoing. A lot depends on where and when you are using the equipment. It also depends on gaining flotation and traction in wet ground or reduced ground disturbance and traction in dry dirt. The main difference between tracks and tires is how they distribute weight, and how this benefits you.

Tires have footprints that contact the ground during the revolution of the tire. The machine’s weight has to be transferred evenly to the ground during these revolutions. The larger the footprint of the tire, the more evenly the weight is distributed, and the less ground bearing pressure it delivers. Tracks have a much greater ground contact area that reduces the tractor weight transfer to the ground. Thus, in theory tracks delivers less pounds per square inch (PSI) of ground bearing pressure than tires. The points of contact of the bogey wheels and drive wheels increase this some.

In terms of traction, tracks work better in wet soil. Tires do as well or better in dry soil. Tracks tend to float across the ground in wet dirt, thus not creating ruts. Tires have to work a little harder in wet soil, and can leave ruts. With the advent of IF and VF tires, you can run lower air pressures to give more foot print, traction, and flotation.

In terms of fuel economy, tracks are designed to work with about 5% slippage. Tire are designed to work with between 8% and 15% slippage, with closer to 8% being optimum. Tracks are possibly a little more fuel efficient with less slippage factored in, but there are other factors to consider, such as the cost of operating and maintaining tracks.

Soil compaction has to be considered when using either one. On average, tracks deliver about 4-8 psi of ground bearing pressure to the soil when parked. This can change some when the tractor is under a drawbar load, and because of track stiffness. The points of contact with the drive wheels and bogey wheels increases this some. Radial tractor tires generally have 1-2 psi higher than their inflation pressure.   IF (Increased Flexion), and VF (Very Increased Flexion) tires were developed to carry the same weight as standard tires with lower air pressures. IF tires will carry 20% more weight at the same air pressure as a standard tire, and VF tires will carry 40% more weight than a standard tire at the same air pressures. If you can run 6-8 psi of air in tires, you are pretty close to tracks.

Tracked tractor suspensions have gotten much better from the early days of tracks. They are more comfortable to drive on the road. While the track manufacturers have much better compounds, there is a lot of set up with the undercarriages for a track installation including alignment, and lubrication.

Tires still seem to work better when a farmer has to move equipment around from farm to farm. Although agricultural tires are not specifically made to run on the road, they still deliver more hours than tracks.

So, which is better? Tracks definitely have an advantage in wet soil. You have heard the old adage, “if it’s too wet in the field, stay out.” Sometimes that is not reality, as crops have to be taken out of the field in the fall, no matter the weather or conditions. This is the purpose of tracks on combines and grain carts. In dry dirt, tires and tracks are pretty close, as far as traction and soil compaction are concerned.

The more serious question is the cost of operating tracks or tires. Although the price of tracks have come down a little, they are still expensive. The cost of maintaining the suspension on tracks is expensive compared to a tractor with tires. On a tractor with tires, you basically only have to worry about tires, wheels, and hubs. There are many more moving parts on a tractor with tracks. While there are advantages and disadvantages to both, a farmer has to decide what is best for his farm, and what costs he can live with.

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)

Scott Sloan:  Ag Product Manager / Global LSW

Tracks vs. Tires has been an ongoing debate in the ag industry for many years.  Depending on what side of the fence you are on each can make the case.  But it really boils down to cost.  Fact is, tracks although they do a fine job in certain applications, the cost to own and operate always catches up with the end user.  From initial purchase cost, ($60K to $100K) more for a track machine over a wheeled machine of the same horsepower, to the inevitable maintenance cost on the tracks which includes not only parts but time to continually lubricate and adjust.

There have been numerous studies that show advantages to both for traction and flotation again depending on the source.  When it comes to compaction the idea that a track has an advantage is a bit of an misnomer.  Flotation and compaction are two different conversations.  In studies, it has been proven that track machines actually have higher ground bearing pressures than a wheeled machine with correctly inflated tires.  Tracks machines tend to be heavier than their wheeled counterpart.  That load is being carried and is concentrated on the bogies and idlers in the track itself not equally distributed across the track.  Since a tire has an air chamber the load is distributed more evenly across the footprint.

With the release of the Goodyear LSW1250/35R46 and the LSW1400/30R46 it has become apparent that a wheeled machine can match the flotation of a track machine with all the advantages of a wheeled machine like higher road speeds with unlimited durations.  Pulling power is identical between the two when tractors are properly ballasted.  We are seeing a major trend moving away from tracks and to the super singles going on in the market place.  OE’s are evaluating and will most likely be offering them in the very near future, and we are looking forward to leading the market with our super single tire innovation.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

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James Tuschner <![CDATA[CFO Tire Explanation & Yield Benefit: Manufacturer’s ANSWER]]> https://agtiretalk.com/?p=948 2018-10-17T01:15:47Z 2018-06-02T21:28:03Z  

Titan International, Inc. (Manufacturer of Titan and Goodyear Farm Tires)

Scott Sloan:  Ag Product Manager / Global LSW

Cyclic Field Operation or CFO designation applies to IF tires.  Per the Tire and Rim Association, the cyclic service is intended for use on a vehicle with a minimal requirement for torque transmission and with appreciable total weight fluctuations, like those on grain carts, combine and air seeders which are repeatedly filled up and emptied. Maximum loads cannot be carried for more than a mile at a time at designated speeds.  CFO allows the IF an increased load capacity of 55% when operating under 10 mph and a 30% when operating 11-20 mph.  The benefit for growers is that if the IF tire is properly inflated it will be operating at a 20% lower inflation pressure compared to its standard tire counterpart which equates to larger footprint and less ground bearing pressure which means less compaction and ultimately higher yields if the conditions are right.

Standard non IF have a similar Cyclic Loading that they abide by.  The definition of cyclic loading is the same, however a standard radial tire operating in a cyclic application may carry 55% more under 10 mph and 70% more under 6 mph with a 25% increase in inflation pressure with a minimum increase of 6 psi and a maximum of 12 psi.

Example:

800/70R38 173A8/B (Conventional Tire)

Standard Application
14,300 lbs at 23 psi

Cyclic  Loading
(+55%)  22,165 lbs at 29 psi cyclic load 10 mph
(+70%)  24,310 lbs at 29 psi cyclic load 6 mph

IF800/70R38CFO 173D (Cyclic Field Operation)

Standard Application
14,300 lbs at 17 psi

Cyclic Loading
(+55%)  22,165 lbs at 17 psi operating under 10 mph

*No additional load bonus for IF under 6 mph

As you can see from this example, there is a 12 psi difference in operating pressures in a cyclic application which would equate to a larger footprint and less ground bearing pressure.  However, one downside to IF in a cyclic application is the 15% loss of additional load capacity under 6mph on tires with identical load indexes, which to some growers may be more important to them than the lower inflation pressure.  Bottom line is I would suggest that growers understand exactly what that piece of equipment weighs no matter what tire they have on it and set the inflation pressure appropriately to ensure they are running with the largest footprint possible to minimize compaction.

CEAT Specialty Tires Inc. 

Jim Enyart:  Technical Manager

The Cyclical Field Operation designation has been utilized for tire inflation recommendations on combines & grain carts where load is accumulated and dispersed during  harvesting operations. The CFO pressure recommendations allow for increased load carrying capacity due to the duration of maximum loads.

In recent years there have been advancements in tire technology with the development of “IF” or increased flexion and “VF” or very high flexion tires. This technology allows a tire to carry about 20% (IF) or 40% (VF) more load at the same inflation pressures as the conventional radial tires or the same load with a respective reduction in inflation pressures as well as having the increased load carrying capacity during cyclic field operations (CFO) during the harvesting process.

Choosing an “IF” or “VF” – “CFO” designated tire would be appropriate when load carrying capacities of standard radial or bias tires are not adequate to carry the maximum loads for combines & grain carts during the harvesting process. This option should also be considered when your harvest season involves wet or muddy field conditions. With increased footprints and additional flotation provided by these tires, growers can increase harvesting opportunities during adverse conditions and may be the difference between harvesting or just salvaging what’s left of your crop. Growers may benefit from reduced ground pressures and compaction but that will depend on many factors including soil moisture, climate and production system among others. Reducing soil compaction contributes to maximizing production and should always be evaluated in every grower’s operation.

Firestone Ag

Bradley J. Harris:  Manager, Global Agricultural Field Engineering

Radial tires that are marked with CFO after the tire size, are IF or VF marked radial tires that are approved to be used on agricultural equipment that experience a significant change in axle load while operating in the field. CFO stands for Cyclic Field Operation and agricultural equipment that would operate under these conditions are combines, grain carts, and air seeders. In cyclic operations, the axle load increase and decreases when harvesting or planting crops.  This additional load is carried at low speeds in the field are not carried on the road.

Before the introduction of IF and VF marked radial tire, bias and standard radial tires had been used on equipment with cyclic loading conditions, but the tires didn’t require any extra identification. The standard developed by The Tire and Rim Association approved cyclic loads with + 6PSI for Field Service Maximum Cyclic Load. The standards allowed extra loading on bias and standard radial tires based on the application and travel speed of the equipment.

When the tire industry introduced the IF and VF marked radial tires, the standards did not allow extra loading based on reduced speed or application. When farmers started to see the benefits of the IF and VF tires on their tractors, they requested to use the IF and VF marked radial tires on their combines and grain carts. To address the requests, the tire industry introduced the CFO standard for the IF and VF marked radial tires. An IF/CFO marked radial tire will still carry 20% more load then a standard radial tire for road transport, but in cyclic service it will carry and additional 55% more load without increasing the inflation pressure.  For farmers concerned about soil compaction during harvest, the higher load capacities of the IF/CFO tires require less inflation pressure. To make this easier to visualize, Chart 1 shows the inflation pressure required for a flotation tire used on a combine. The chart compares similarly sized bias, standard radial and IF/CFO radial tires. The axle load for each class of combine is an approximate maximum cyclic weight for the machine. This is just a general comparison, please consult your operator’s manual for axle loads to determine the inflation pressure required on your combine.

Chart 1: Tire inflation pressure (psi) based on cyclic axle load (lbs.)

In the chart, a class 8 combine has a cyclic axle weight of 60,000 lbs. To be able to carry the load, a 76×50.00-32 bias tire requires 36 psi, a 1250/50R32 standard radial requires 28 psi, and the IF 1250/50R32 CFO radial requires 19 psi. If a farmer is trying to limit ground compaction, they would want the IF/CFO tire on the combine.

The major benefit of using CFO tires on harvest and seeding equipment is being able to carry the axle load at lower inflation pressures compared to the same sized standard radial or bias. The lower inflation pressure help reduce soil compaction in wet conditions. The IF/CFO tires will also have a larger footprint vs a standard radial, helping increase flotation during a wet harvest. On larger grain carts, the IF/CFO tires may have enough load capacity allowing customers to still use one axle instead of multiple axles or tracks and control equipment cost. The CFO marked tires are just another tool customer’s have to help minimize soil compaction as the equipment gets larger.

Alliance Tire Americas

James Crouch:  Marketing Specialist

Cyclical Field Operation, or CFO, is a 55% load bonus given to specially designed and constructed IF tires while that tire is being used in a “cyclical” condition and operating at or below 10 mph. “Cyclical” means that the load applied on the tire is in constant flux during the normal operation of the machine on which the tires are fitted; the tires are engineered and built to handle the fluctuating load, including its peaks. The perfect and purest example of this application is a combine during harvest.

Consider the combine moving through a soybean field. The combine is moving at 6 mph and is using its header to harvest beans. The harvested beans move into the feeder house, through the separator and then are deposited into the grain bin of the machine. At the same time, the combine is actively transferring the harvested beans from the on-board grain bin into a grain cart that is following closely beside. During this time, the weight of the soybeans is a live load—their weight is flowing through the combine and then out to the grain cart, shifting from tire to tire. Ultimately, their weight is never constantly being applied to the tires.

A “live,” fluctuating load—like grain at harvest or a spray tank during application—is the only type of load that can take advantage of the CFO tire’s load bonus. CFO tires are exceptionally strong, but they are NOT designed for sustained extra-high loads.

The CFO load bonus is only found on IF and VF tires. IF (Increased Flexion) tires offer a 20% load capacity bonus over a standard radial while VF (Very High Flexion) tires offer a 40% load bonus compared to a standard radial. When you focus simply on load capacity in cyclic operation, a VF CFO tire provides 186% of the capacity of a standard radial tire for peak load in a cyclic operation with no air pressure adjustments. (100% of the conventional radial capacity x 1.40 for the 40% VF bonus, x 1.33 for the 33% CFO bonus = 186%.)

This ability to handle massive spikes in load is a must-have for today’s harvesters. These machines have seen a more significant increase in weight than most other pieces of equipment over the last several years. The introduction of VF CFO technology has allowed equipment manufacturers to offer pneumatic solutions for harvesters that carry the load while putting minimum amounts of pressure on the soil. Minimizing soil compaction is increasingly important. The front axle of a loaded combine can weigh as much as a properly ballasted four-wheel drive tractor.

It would be perfectly possible to carry the loads required by today’s combines with a standard radial tire. However, the air pressures needed to do this job would be incredibly high. A good rule of thumb is that for every psi in the tire, the machine exerts roughly 1.1x that pressure as compaction force into the soil.

For example, farmers can buy a 800/70R38 tire with very high load capacity. But until the advent of VF CFO technology, the only way for a tire that size to carry the load of one of today’s massive combines, filled, was to operate at around 50 psi. That creates a very hard ride and, even more important, means the tires would be pushing down on the soil with a force of about 55 psi. That’s enough force, in many conditions, to create a deep compaction zone that would restrict root growth, water infiltration and air supply.

800/70R38 181A8/B (Conventional Tire)
Standard Application
18,200 lbs. at 41 psi

Cyclic Loading
(+55%) 28,200 lbs. at 47 psi cyclic load 10 mph
(+70%) 30,900 lbs. at 47 psi cyclic load 6 mph

VF800/70R38CFO 181E (Cyclic Field Operation)
Standard Application
18,200 lbs. at 23 psi

Cyclic Loading
(+33%) 24,200 lbs. at 23 psi operating under 10 mph
*No additional load bonus for VF under 6 mph

In short, VF CFO requires 40% less air pressure to carry standard load, and 50% less air pressure to achieve above cyclical load bonuses.

At Alliance, we believe that every modern harvester—and large self-propelled application equipment—needs at least an IF CFO tire and preferably a VF CFO. The loads are simply too high and the cost of compaction is too severe. To show our commitment in improving the situation, we are expanding our Agriflex Technology product line for harvesters to include VF CFO technology in as many sizes as the market requires.

Trelleborg Wheel Systems

Norberto Herbener:  OE Applications Engineer

Not all tires are used for the same operation and for that reason additional features have been added to several tire sizes to be more efficient and adaptable to a specific performance need.

One specific kind of tire “enhancement” is the Cyclical capability. This kind of concept applies mainly, but not limited to, combines and grain carts where the load on the tires changes during field operation. During harvest the combine unit (combine plus header and any additional accessories) starts in the field with a specific weight (combine unit weight plus fuel) that is the lowest weight on the field of the combine unit. When the combine unit begins harvesting, the grain is collected in the grain bin, increasing the total weight of the combine unit until reaching a maximum weight when the grain bin is full. The combine unit returns to its lowest weight as soon as the grain bin is emptied and the cycle starts again. This is the concept of cyclic – increasing and decreasing weight.

In a normal operation, a tire generates a certain amount of heat due to the internal rubber friction. This is considered during development of the tire. If the tire is overloaded with more than it is designed to handle, the tire’s temperature will rise and create internal damage to the tire, accelerate wear and potentially separate the tread. A tire designed for cyclical operation takes into account this increase in heat and is reinforced internally to withstand this “temporary” overload.

A tire designed as cyclical will be marked on the sidewall the denomination of CHO (Cyclic Harvest Operation) when it is a conventional tire and CFO (Cyclic Field Operation) if its applied to an IF or VF technology tire.

On a conventional tire, considering the same inflation pressure, the load capacity increases when the working speed is reduced. On a CHO designed tire, the temporary overload permitted is 65% at 9 mph or 80% at 6 mph based on the load capacity at the tire rated speed. For example, the load capacity of an 800/70R38 CHO 178D at 35 PSI is 16.530 lbs. (178) and 40 mph (D). The cyclic overload allows to this tire to resist – at 35 PSI – 27.280 lbs. at 9 mph or 29.760 lbs. at 6 mph. In comparison, a non-CHO version of the same tire would hold only 23.150 lbs. at 6 mph with no air pressure increase.

800/70R38 178D (Conventional Tire)

Standard Application
16,530 lbs. at 35 psi at 40 mph
23,150 lbs. at 35 psi at 6 mph

800/70R38CHO 178D (Cyclic Harvest Operation)

Standard Application
16,530 lbs. at 35 psi at 40 mph

Cyclic Loading
(+65%)  27,280 lbs. at 35 psi cyclic load 9 mph
(+80%)  29,760 lbs. at 35 psi cyclic load 6 mph

At equivalent 35 psi, above CHO Cyclical Harvest Operation tire enables 80% Cyclic Load Bonus at 6 mph, whereas Standard Tire enables 40% Load Bonus at 6 mph.  A big difference!

The same temporary overload concept is applied on IF and VF tires. These tires are designed to withstand higher loads with the overload bonuses lower than on conventional tires. On an IF CFO tire the overload bonus is reduced to 55% and to 33% on a VF CFO tire. This is considering the same inflation pressure and using the same base load capacity at the rated speed and inflation pressure.

What does this mean to the end user?  The tires are stronger and heavier but the main advantage is the possibility to reduce inflation pressure with a larger footprint and less soil compaction. When considering what inflation pressure to use, we must know the maximum load the tire can carry at a certain speed.

As an example, (all approximate and rounded values) a Class 7 combine with a 12 row corn head would have a total empty weight of 48.000 lbs. and 66.000 lbs. when the 300-bushel grain bin is full of soybeans.

Considering that the front wheel supports 75% of that load, each tire would need to hold 18.000 lbs. (48.000 lbs. * 0.75 /2 tires) when empty and 25.000 lbs. (66.000 lbs. * 0.75/2 tires) when the grain bin is full. When checking the tire inflation tables for this specific tire size, and choosing 6 mph as a normal working speed during harvest, the non-CHO tire would need an inflation pressure of 29 PSI to hold the 25.000 lbs. when full. The CHO tire, thanks to the cyclical bonus, would only need 23 PSI to hold the same 25.000 lbs. when full. This means that the CHO version needs 6 PSI less inflation pressure.

Less inflation pressure means larger footprint, reduced soil compaction, better crop development and higher yields. A win-win situation.

BKT USA, Inc.

Dave Paulk:  Manager Field Technical Services

Cyclical Field Operation (CFO) tires are specifically designed for use on combines, cotton pickers, and grain carts, where varying loads and reduced soil compaction is important to increasing productivity.  The IF/CFO design allows for an increase in load carrying capacity, while not having to increase the air pressure. These tires are designed to carry more weight than the same size conventional radial tires and are constructed to withstand the extreme load changes that exist during harvesting. Since load weights are constantly changing- empty to full to empty again- the tires are given a 55% cyclic load bonus at 0-10 mph without having to increase the air pressure.

One benefit is that the IF/CFO rated tire can reduce ground bearing pressure and soil compaction, since it carries 20% more weight than the standard tire at the same air pressure. Another feature is that the air pressure can be reduced to carry the same weight as a standard tire, which also reduces soil compaction. Reduced soil compaction in the field equates to higher yields year over year. In addition, CFO tires can harvest larger quantities with less stoppage time, therefore increasing the farmers’ productivity. In some applications such as with grain carts, the IF/CFO tires are needed to carry the heavy axle loads. Remember that correct air pressure for the load is important when soil compaction is an issue.

Michelin Ag

David Graden: Operational Market Manager – Agriculture

Cyclical Field Operation (CFO) rated tires are designed with technology that allow higher carrying capacity without increasing air pressure during field work and typically found on harvest machinery and grain carts. Harvesters today are heavier than they have ever been. It is becoming more common to see hopper extensions, larger and folding corn heads, 18 row corn heads, etc. These machines are asking more than our standard tires can offer. Therefore, growers need to consider fitting their machines with CFO tires. Not only does a grower gain the additional carrying capacity without increasing air pressure, but he/she will also see an increase in productivity due to traction and flotation in damp soils and significantly lower soil compaction. As a byproduct, they should also see an increase in yield.

It is also important to note performance difference between IF CFO & VF CFO tires. In the summer of 2016, Michelin participated in the Ag PhD show in Baltic, SD at the Hefty Brothers farm.  A soil compaction pit was produced to show the reduction in shallow and deep compaction as well as the overall rutting of the VF CFO tire compared to IF CFO harvest tire of the same size.

Using Hefty’s Case 9120 combine with a Capella folding 12 row head and a full hopper (approximately 350 bushel of corn), one side of the machine was mounted with Michelin VF CFO and the other side with IF CFO tires.  The combine was weighed and showed 61,350 pounds in this configuration when fully loaded, air pressures were set in accordance with load indexes, and then the combine, in this configuration, was driven on and off the soil compaction pit.

Once we fully revealed the layers of the pit and did the analysis, the results were striking.  Our VF CFO tire was able to run at 24psi vs IF CFO tire at 36psi (50% air pressure increase required for IF CFO).   We showed a nearly 6% larger footprint when looking at square inches of tire on the ground.  Finally, we reduced rutting in the same soil by 20%.

Bottom line, CFO rated tires are a great fit for almost all harvesting situations. However, not all CFO tires are the same. I recommend end users do their research. Understand the difference between IF, VF, IF CFO, VF CFO and variance in load indexes.  Any gain in yield goes to your bottom line.

All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.

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